[wayland]: keyboard shortcuts inhibitor “active” not sent

Protocol reads:

This event indicates that the shortcut inhibitor is active.

The compositor sends this event every time compositor shortcuts are inhibited on behalf of the surface. When active, the client may receive input events normally reserved by the compositor (see zwp_keyboard_shortcuts_inhibitor_v1).

This occurs typically when the initial request "inhibit_shortcuts" first becomes active or when the user instructs the compositor to re-enable and existing shortcuts inhibitor using any mechanism offered by the compositor.

https://cgit.freedesktop.org/wayland/wayland-protocols/tree/unstable/keyboard-shortcuts-inhibit/keyboard-shortcuts-inhibit-unstable-v1.xml

But mutter sends the event only when the surface is focused. Trivial patch to follow.