use DECLARE_NO_COPY_CLASS() where applicable (patch 633384)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@18525 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/valtext.h

@@ -95,6 +95,14 @@ protected:
 
         return TRUE;
     }
+
+private:
+// Cannot use
+//  DECLARE_NO_COPY_CLASS(wxTextValidator)
+// because copy constructor is explicitly declared above;
+// but no copy assignment operator is defined, so declare
+// it private to prevent the compiler from defining it:
+    wxTextValidator& operator=(const wxTextValidator&);
 };
 
 #endif