GXK: fix compiler warnings about switch type
GXK: fix compiler warnings about switch type

GNOME/beast,GNOME/beast,swesterfeld/beast,swesterfeld/beast,GNOME/beast,swesterfeld/beast,tim-janik/beast,tim-janik/beast,tim-janik/beast,tim-janik/beast,GNOME/beast,GNOME/beast,swesterfeld/beast,swesterfeld/beast,tim-janik/beast,tim-janik/beast,swesterfeld/beast,swesterfeld/beast,GNOME/beast,tim-janik/beast,GNOME/beast