[Qt] fix a issue where "command line options"-action overwrite "Preference"-action (on OSX)

- fixes #5800

src/qt/bitcoingui.cpp

@@ -340,6 +340,7 @@ void BitcoinGUI::createActions()
     openAction->setStatusTip(tr("Open a bitcoin: URI or payment request"));
 
     showHelpMessageAction = new QAction(TextColorIcon(":/icons/info"), tr("&Command-line options"), this);
+    showHelpMessageAction->setMenuRole(QAction::NoRole);
     showHelpMessageAction->setStatusTip(tr("Show the Bitcoin Core help message to get a list with possible Bitcoin command-line options"));
 
     connect(quitAction, SIGNAL(triggered()), qApp, SLOT(quit()));