Fix #139: Recent Files was broken on MacOS.

cf OpenFlipper-Free#139

widgets/coreWidget/CoreWidget.cc

@@ -952,7 +952,11 @@ CoreWidget::updateRecent()
     }
 
   }
-
+  // Workaround for QMenu issue on MacOS: https://bugreports.qt.io/browse/QTBUG-63848
+  // Without this, the recent files menu entries are all disabled after using the menu once:
+  // https://www.graphics.rwth-aachen.de:9000/OpenFlipper-Free/OpenFlipper-Free/issues/139
+  recentFilesMenu_->setEnabled(false);
+  recentFilesMenu_->setEnabled(true);
 }
 
 void