Won't sync with NTP if module can't access internet

[TheGroundZero]

Issue

For more background information, see jnthas/clockwise#39

As per JeffWDH's investigation, this module will (attempt to) connect to timezoned.rop.nl on port udp/2342 before connecting to a (custom) NTP server.
If this request to timezoned fails, it will not continue connecting to the NTP server.

As a result, this module won't correctly set the time on a device that's not connected to the internet, even if it's configured to use a locally-hosted NTP server.

Solution

The module should not rely on a connection on the internet.
As a mimum, a failed connection to timezoned.rop.nl should not stop the further process of syncing to a (manually configured) NTP server.

[TheGroundZero]

As the connection to timezones is only to turn a timezone name into an POSIX string, maybe this string could be provided by the application including this module?