message: use "---" placeholder for empty save games
diff: @@ -904,7 +904,7 @@ void GameMenu::updateSavTitle(GameMenu::Item& sel) {
  std::snprintf(fname,sizeof(fname)-1,"save_slot_%d.sav",int(id));
  if(!FileUtil::exists(TextCodec::toUtf16(fname))) {
  - sel.handle.text[0] = "";
  + sel.handle.text[0] = "---";
  return;
  }
  