Fix typos causing build failures on non-macOS systems

It also did the exact opposite thing I was trying to do, so that's fixed too...

launcher/ui/MainWindow.h

@@ -186,9 +186,11 @@ private slots:
 
     void globalSettingsClosed();
 
+#ifndef Q_OS_MAC
     void keyReleaseEvent(QKeyEvent *event) override;
 
     void keyPressEvent(QKeyEvent *event) override;
+#endif
 
 private:
     void retranslateUi();