As we don't give out information about the group or level when
giving back keycodes, we should prioritise group-0, level-0, followed by
level-0 only, and then any keycodes.

This fixes "q" being pressed when the Wacom tablet code in
gnome-settings-daemon is supposed to generate an "a" ("uk" keymap
in group-0, "fr" in group-1).

https://bugzilla.gnome.org/show_bug.cgi?id=671065