Copy network authority when instancing placeholder nodes.

scene/main/instance_placeholder.cpp

@@ -93,6 +93,7 @@ Node *InstancePlaceholder::create_instance(bool p_replace, const Ref<PackedScene
 		return nullptr;
 	}
 	scene->set_name(get_name());
+	scene->set_multiplayer_authority(get_multiplayer_authority());
 	int pos = get_index();
 
 	for (const PropSet &E : stored_values) {