wayland: Clean up key repeat timeout

When returning G_SOURCE_REMOVE from a callback, we need
to reset the source id as well.

gdk/wayland/gdkdevice-wayland.c

@@ -1804,6 +1804,8 @@ keyboard_repeat (gpointer data)
                             &sync_after_repeat_callback_listener,
                             device);
 
+  device->repeat_timer = 0;
+
   return G_SOURCE_REMOVE;
 }