Protect WaitDialog from garbage collector

qtgui/mainwindow.py

@@ -223,7 +223,7 @@ class MainWindow(QtWidgets.QMainWindow):
         settings.remove("programDatabase")
 
         logger.info("Asking api to getSystemPrograms while waiting")
-        WaitDialog(self, title, text, informativeText, api.buildSystemPrograms)        
+        diag = WaitDialog(self, title, text, informativeText, api.buildSystemPrograms) #save in local var to keep alive
         settings.setValue("programDatabase", api.getSystemPrograms())
         self._updateGUIWithCachedPrograms()