wayland-client : Fix queue_release not to call proxy_destroy

proxy_destroy could be called twice by wl_proxy_destroy and wl_event_queue_release.
Then, wl_map_remove was called twice for same object id.

Signed-off-by: Elvis Lee <kwangwoong.lee@lge.com>
Reviewed-by: Jonas Ådahl <jadahl@gmail.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>