gsettings: Suppress error messages of completion
gsettings: Suppress error messages of completion

https://bugzilla.gnome.org/show_bug.cgi?id=695681

johne53/MB3Glib,endlessm/glib,johne53/MB3Glib,johne53/MB3Glib,endlessm/glib,endlessm/glib,johne53/MB3Glib,johne53/MB3Glib,endlessm/glib,endlessm/glib,johne53/MB3Glib