Bugs of the Gdm themes

[Loïc Minier <lool+debian@via.ecp.fr>]

        Hi,

 #404502 and #407038 are preventing desktop-base from migrating to
 testing.

 As I don't use Gdm myself, it would be nice if someone else could look
 into these issues.

   Thanks,
-- 
Loïc Minier <lool@dooz.org>