Document that wxRadioBox::SetSelection() doesn't accept wxNOT_FOUND.

A radio box always has selection and it can't be unset (at least not under all
platforms), so document that the item passed to its SetSelection() must be
valid, unlike with SetSelection() methods in some other classes.

Closes #15233.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74073 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/radiobox.h

@@ -287,6 +287,14 @@ public:
     */
     void SetItemToolTip(unsigned int item, const wxString& text);
 
+    /**
+        Sets the selection to the given item.
+
+        Notice that a radio box always has selection, so @a n must be valid
+        here and passing @c wxNOT_FOUND is not allowed.
+     */
+    virtual void SetSelection(int n);
+
     /**
         Shows or hides individual buttons.
 
@@ -310,7 +318,6 @@ public:
     virtual unsigned int GetCount() const;
     virtual wxString GetString(unsigned int n) const;
     virtual void SetString(unsigned int n, const wxString& string);
-    virtual void SetSelection(int n);
     virtual int GetSelection() const;
 
 };