Fixes CollisionShape extends not updating when draggind handles

editor/plugins/collision_shape_2d_editor_plugin.cpp

@@ -203,6 +203,7 @@ void CollisionShape2DEditor::set_handle(int idx, Point2 &p_point) {
 
 		} break;
 	}
+	node->get_shape()->_change_notify();
 }
 
 void CollisionShape2DEditor::commit_handle(int idx, Variant &p_org) {