[SAC] Gogs upgraded from 0.9.27 to 0.9.68

I've upgraded Gogs from a customized version
to a vanilla version

The new version includes the modifications previously only
present in our own fork (namely: properly encoded notification
emails and libravatar support).

The new version also fixes automatic setting of user language:

Please let me know if you find any problem with the new version
(possibly via tickets to https://git.osgeo.org/gogs/sac/gogs-service)

Thanks, and happy holidays !