Fix use of persistent instances of ERP5 Base outside of portal

This fixes testSelectionTool.TestSelectionPersistence.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@45080 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/dynamic/persistent_migration.py

@@ -176,7 +176,10 @@ if 1:
     if portal_type == 'Dummy Class Tool':
       return Base__setstate__(self, value)
     # proceed with migration
+    try:
       self._fixPortalTypeBeforeMigration(portal_type)
+    except IndexError: # getSite raised
+      return Base__setstate__(self, value)
     import erp5.portal_type
     newklass = getattr(erp5.portal_type, portal_type)
     assert self.__class__ is not newklass