Uncheck radiobutton when calling ::SetValue(false) as per wxMSW, fixes #12344: Cannot set GTK wxRadioButton to fasle

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65323 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/radiobut.cpp

@@ -123,6 +123,8 @@ void wxRadioButton::SetValue( bool val )
         // should give an assert
         // RL - No it shouldn't.  A wxGenericValidator might try to set it
         //      as FALSE.  Failing silently is probably TRTTD here.
+        // RR - MSW actually unchecks the radio button so do this here, too
+        gtk_toggle_button_set_active( GTK_TOGGLE_BUTTON(m_widget), FALSE );
     }
 
     g_signal_handlers_unblock_by_func(