Fixes AC_CHECK_HEADER for issue #3

[j-lowry]

#3

https://www.gnu.org/software/autoconf/manual/autoconf-2.64/html_node/Present-But-Cannot-Be-Compiled.html

Still not finding dssl/sslcap.h but at least the error message is a little nicer. Here is the new snippet on Ubuntu 12.04.2 LTS:
"
.
.
.
checking openssl/ssl.h usability... yes
checking openssl/ssl.h presence... yes
checking for openssl/ssl.h... yes
checking for dssl/sslcap.h... no
configure: error: libdssl header file not found. https:/downloads/plashchynski/viewssld/libdssl-2.1.1.tar.gz
jlowry@lappie:~/src/c/viewssld$
.
.
.
"

[ankitjaingc]

/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:777: undefined reference to SessionToString' viewssld.o: In functioninit_fake_session_state':
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:409: undefined reference to libnet_init' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:425: undefined reference tolibnet_seed_prand'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:438: undefined reference to libnet_get_prand' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:439: undefined reference tolibnet_get_prand'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:432: undefined reference to libnet_destroy' viewssld.o: In functionsendEmptyTCPSegment':
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:536: undefined reference to libnet_build_tcp' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:560: undefined reference tolibnet_build_ipv4'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:584: undefined reference to libnet_build_ethernet' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:596: undefined reference tolibnet_geterror'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:556: undefined reference to libnet_geterror' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:602: undefined reference tolibnet_write'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:611: undefined reference to libnet_clear_packet' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:578: undefined reference tolibnet_geterror'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:554: undefined reference to libnet_geterror' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:605: undefined reference tolibnet_geterror'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:598: undefined reference to libnet_geterror' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:580: undefined reference tolibnet_geterror'
viewssld.o:/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:607: more undefined references to libnet_geterror' follow viewssld.o: In functionsession_event_handler':
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:448: undefined reference to SessionToString' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:500: undefined reference topcap_stats'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:512: undefined reference to libnet_destroy' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:466: undefined reference toSessionSetCallback'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:468: undefined reference to SessionSetMissingPacketCallback' viewssld.o: In functiondata_callback_proc':
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:680: undefined reference to libnet_build_tcp' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:714: undefined reference tolibnet_build_ipv4'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:738: undefined reference to libnet_build_ethernet' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:750: undefined reference tolibnet_geterror'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:766: undefined reference to libnet_clear_packet' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:680: undefined reference tolibnet_build_tcp'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:708: undefined reference to libnet_geterror' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:756: undefined reference tolibnet_write'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:759: undefined reference to libnet_geterror' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:732: undefined reference tolibnet_geterror'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:710: undefined reference to libnet_geterror' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:752: undefined reference tolibnet_geterror'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:734: undefined reference to libnet_geterror' viewssld.o:/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:761: more undefined references tolibnet_geterror' follow
viewssld.o: In function main': /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:238: undefined reference toSSL_library_init'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:239: undefined reference to OpenSSL_add_all_ciphers' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:240: undefined reference toOpenSSL_add_all_digests'
viewssld.o: In function proceed': /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:317: undefined reference topcap_open_live'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:329: undefined reference to pcap_compile' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:334: undefined reference topcap_setfilter'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:343: undefined reference to CapEnvCreate' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:345: undefined reference toCapEnvSetSSL_ServerInfo'
viewssld.o: In function main': /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:244: undefined reference toEVP_cleanup'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:245: undefined reference to CRYPTO_cleanup_all_ex_data' viewssld.o: In functionproceed':
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:372: undefined reference to CapEnvDestroy' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:378: undefined reference topcap_close'
viewssld.o: In function main': /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:244: undefined reference toEVP_cleanup'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:245: undefined reference to CRYPTO_cleanup_all_ex_data' viewssld.o: In functionproceed':
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:358: undefined reference to CapEnvSetSessionCallback' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:360: undefined reference toCapEnvCapture'
/home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:336: undefined reference to pcap_geterr' /home/aman/Desktop/viewssld-0.7.0/src/viewssld.c:331: undefined reference topcap_geterr'
collect2: ld returned 1 exit status
make[1]: *** [viewssld] Error 1
make[1]: Leaving directory /home/aman/Desktop/viewssld-0.7.0/src' make: *** [check-recursive] Error 1 make: Leaving directory/home/aman/Desktop/viewssld-0.7.0'

[plashchynski]

Thank you!