gdbus: Work around threading deadlock in glib
gdbus: Work around threading deadlock in glib

See https://bugzilla.gnome.org/show_bug.cgi?id=674885
for more details.  What dconf is doing right now provokes
this more easily by involving *another* thread in the mix.

GNOME/dconf,GNOME/dconf,GNOME/dconf,GNOME/dconf