xdgmime: Don’t set an out argument if it’s NULL
See https://gitlab.gnome.org/GNOME/glib/merge_requests/733.
Signed-off-by: Philip Withnall withnall@endlessm.com
See https://gitlab.gnome.org/GNOME/glib/merge_requests/733.
Signed-off-by: Philip Withnall withnall@endlessm.com