Display ToolStrip RadioButton menu items as checkboxes

Author: sergiye

rdpWrapper/MainForm.cs

@@ -270,6 +270,7 @@ private void btnClose_Click(object sender, EventArgs e) {
 
     private void InitializeTheme() {
 
+      ToolStripRadioButtonMenuItem.DisplayAsCheckboxes = true;
       mainMenu.Renderer = new ThemedToolStripRenderer();
 
       var currentItem = CustomTheme.FillThemesMenu((title, theme, onClick) => {