Treat empty strings from gconf as nulls.
Treat empty strings from gconf as nulls.

Tarnyko/rygel,GNOME/rygel,Tarnyko/rygel,GNOME/rygel,Pelagicore/Media-Manager-Rygel-patched,jku/rygel,Pelagicore/Media-Manager-Rygel-patched,luisbg/rygel,jku/rygel,GNOME/rygel,Pelagicore/Media-Manager-Rygel-patched