message: Fix NullReferenceException (win)
diff: @@ -23,7 +23,7 @@ namespace TogglDesktop
  protected override void OnStartupNextInstance(Microsoft.VisualBasic.ApplicationServices.StartupNextInstanceEventArgs e)
  {
  - app.MainWindow.ShowOnTop();
  + app.MainWindow?.ShowOnTop();
  }
  }
  }
  \ No newline at end of file
  