better patch

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@2420 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Form/FormulatorPatch.py

@@ -624,5 +624,6 @@ class PatchedDateTimeWidget(DateTimeWidget):
         else:
             return date_result
         
-DateTimeWidget.render = PatchedDateTimeWidget.render      
+PatchedDateTimeWidgetInstance = PatchedDateTimeWidget()
+DateTimeField.widget = PatchedDateTimeWidgetInstance