optical-media: Don't recurse when looking for DVDs
optical-media: Don't recurse when looking for DVDs

It shouldn't do it, but this ensures that we don't try if we
get the wrong URI by mistake.

https://bugzilla.gnome.org/show_bug.cgi?id=696863

MikePetullo/grilo-plugins,kyoushuu/grilo-plugins,kyoushuu/grilo-plugins,kyoushuu/grilo-plugins,grilofw/grilo-plugins,MikePetullo/grilo-plugins,MathieuDuponchelle/grilo-plugins,MikePetullo/grilo-plugins,grilofw/grilo-plugins,jasuarez/grilo-plugins,MathieuDuponchelle/grilo-plugins,MathieuDuponchelle/grilo-plugins,MathieuDuponchelle/grilo-plugins,vrutkovs/grilo-plugins,jasuarez/grilo-plugins,vrutkovs/grilo-plugins,GNOME/grilo-plugins,vrutkovs/grilo-plugins,vrutkovs/grilo-plugins,GNOME/grilo-plugins