keyfile: explicitly use local GVfs
keyfile: explicitly use local GVfs

Avoid initialising all of GVfs for dconf-service in order to monitor a
local file for changes.

See https://bugzilla.gnome.org/show_bug.cgi?id=691618 for the
possibility of a better fix.

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