tigervnc: fix a regression in VncAuth security type

tigervnc v1.14.0 introduced a regression
in its list of supported security types:
Due to a missing comma in the code,
the VncAuth security type (i.e. simple password check) isn't
tried unless it is explicitely requested on the command line:

TigerVNC/tigervnc#1789

The commit at hand adds a patch from upstream
(which will most likely be part of the next release)
to fix this oversight.

pkgs/tools/admin/tigervnc/default.nix

@@ -1,6 +1,7 @@
 { lib
 , stdenv
 , fetchFromGitHub
+, fetchpatch
 , xorg
 , xkeyboard_config
 , zlib
@@ -33,6 +34,14 @@ stdenv.mkDerivation rec {
  sha256 = "sha256-TgVV/4MRsQHYKpDf9L5eHMLVpdwvNy1KPDIe7xMlQ9o=";
  };
 
+ patches = [
+ (fetchpatch {
+ name = "vncauth-security-type.patch";
+ url = "https:/TigerVNC/tigervnc/commit/4f6a3521874da5a67fd746389cfa9b6199eb3582.diff";
+ hash = "sha256-lSkR8e+jsBwkQUJZmA0tb8nM5iSbYtO8uVXtgk5wdF8=";
+ })
+ ];
+
  postPatch = lib.optionalString stdenv.hostPlatform.isLinux ''
  sed -i -e '/^\$cmd \.= " -pn";/a$cmd .= " -xkbdir ${xkeyboard_config}/etc/X11/xkb";' unix/vncserver/vncserver.in
  fontPath=