gpgconf, w32: Allow UNC paths
* tools/gpgconf-comp.c (get_config_filename): Allow UNC paths.
The homedir of GnuPG on Windows can be on a network share
e.g. if %APPDATA% is redirected to a network share. The
file API calls work and GnuPG itself works nicely
with such paths so gpgconf should work with them, too.
- GnuPG-Bug-Id: T3818
- Signed-off-by: Andre Heinecke <firstname.lastname@example.org>