wxEndBusyCursor() was being called, even when it was not needed, causing a wxAssert in debug mode

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@4434 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/db/listdb.cpp

@@ -406,7 +406,7 @@ void ClookUpDlg::OnClose(wxCloseEvent& event)
 	if (lookup2)
 		delete lookup2;
 
-	wxEndBusyCursor();
+	while (wxIsBusy()) wxEndBusyCursor();
    event.Skip();
 
 //	return TRUE;