Remove useless 'print_exc'

It does not show more information than following LOG.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@41772 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/dynamic/lazy_class.py

@@ -205,7 +205,6 @@ class PortalTypeMetaClass(GhostBaseMetaClass):
       try:
         class_definition = generatePortalTypeClass(portal_type)
       except AttributeError:
-        import traceback; traceback.print_exc()
         LOG("ERP5Type.Dynamic", WARNING,
             "Could not access Portal Type Object for type %r"
             % portal_type, error=sys.exc_info())