Destroy the registry when WaylandConfig gets deleted
A pointer to WaylandConfig gets passed to wl_registry_add_listener but this is global and can trigger also when WaylandConfig has just been deleted and wl_registry is leaking
(cherry picked from commit 035f3c2d)
da99bb03 destroy the callback when WaylandConfig gets deleted 32d13ab6 destroy the registry fabf6ec9 adress comments b2dfe208 removedead code
Co-authored-by: Marco Martin notmart@gmail.com