Send key array when losing focus too.

The compositor tracks this anyway, and the client will typically need
this to post key release events and adjust modifier status.
diff --git a/wayland-system-compositor.c b/wayland-system-compositor.c
index 5524dbb..1a28f76 100644
--- a/wayland-system-compositor.c
+++ b/wayland-system-compositor.c
@@ -871,7 +871,7 @@
 	    (!surface || device->keyboard_focus->base.client != surface->base.client))
 		wl_surface_post_event(&device->keyboard_focus->base,
 				      &device->base,
-				      WL_INPUT_KEYBOARD_FOCUS, NULL, NULL);
+				      WL_INPUT_KEYBOARD_FOCUS, NULL, &device->keys);
 
 	if (surface)
 		wl_surface_post_event(&surface->base,