Correct a bug occur when trying to add a new role definition with older role definition

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@3799 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/RoleInformation.py

@@ -146,7 +146,7 @@ class RoleInformation( SimpleItem ):
                              , condition=self.getCondition()
                              , priority =self.priority
                              , base_category=self.base_category
-                             , base_category_script=self.base_category_script
+                             , base_category_script=getattr(self, 'base_category_script', '')
                              )
 
 InitializeClass( RoleInformation )