Fix crash on debug shapes update if CollisionObject is not in tree

Also fix ConcavePolygonShape not emitting the changed signal

(cherry picked from commit 7043d6d1c683357f311d83ffd5b8cf2669283e1b)

scene/3d/collision_object.cpp

@@ -160,6 +160,11 @@ void CollisionObject::_shape_changed(const Ref<Shape> &p_shape) {
 }
 
 void CollisionObject::_update_debug_shapes() {
+	if (!is_inside_tree()) {
+		debug_shapes_to_update.clear();
+		return;
+	}
+
 	for (Set<uint32_t>::Element *shapedata_idx = debug_shapes_to_update.front(); shapedata_idx; shapedata_idx = shapedata_idx->next()) {
 		if (shapes.has(shapedata_idx->get())) {
 			ShapeData &shapedata = shapes[shapedata_idx->get()];

scene/resources/concave_polygon_shape.cpp

@@ -71,6 +71,7 @@ void ConcavePolygonShape::_update_shape() {
 void ConcavePolygonShape::set_faces(const PoolVector<Vector3> &p_faces) {
 
 	PhysicsServer::get_singleton()->shape_set_data(get_shape(), p_faces);
+	_update_shape();
 	notify_change_to_owners();
 }