Added default constructor to MenuBarComponent

modules/juce_gui_basics/menus/juce_MenuBarComponent.h

@@ -41,10 +41,10 @@ public:
     /** Creates a menu bar.
 
         @param model    the model object to use to control this bar. You can
-                        pass nullptr into this if you like, and set the model
-                        later using the setModel() method
+                        pass omit the parameter or pass nullptr into this if you like,
+                        and set the model later using the setModel() method.
     */
-    MenuBarComponent (MenuBarModel* model);
+    MenuBarComponent (MenuBarModel* model = nullptr);
 
     /** Destructor. */
     ~MenuBarComponent();