fix #289651: show courtesy checkbox not working in clef inspector

mscore/inspector/inspector.cpp

@@ -954,7 +954,8 @@ void InspectorClef::setElement()
 void InspectorClef::valueChanged(int idx)
       {
       // copy into 'other clef' the ShowCouretsy ser of this clef
-      if (idx == 6 && otherClef)
+      Pid pid = iList[idx].t;
+      if (pid == Pid::SHOW_COURTESY && otherClef)
             otherClef->setShowCourtesy(c.showCourtesy->isChecked());
       InspectorBase::valueChanged(idx);
       }