message: fixed extenders in threaded builds
diff: @@ -851,6 +851,7 @@ public:
  void MenuPyBuilder(FMenuBuilder &Builder)
  {
  + FScopePythonGIL gil;
  PyObject *ret = PyObject_CallFunction(py_callable, (char *)"O", py_ue_new_fmenu_builder(Builder));
  if (!ret)
  {
  @@ -868,6 +869,7 @@ public:
  void ToolBarBuilder(FToolBarBuilder &Builder)
  {
  + FScopePythonGIL gil;
  PyObject *ret = PyObject_CallFunction(py_callable, (char *)"O", py_ue_new_ftool_bar_builder(Builder));
  if (!ret)
  {
  