Fix error in previous commit

fallback to previous default value only if parameter is _MARKER


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@36032 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/BusinessTemplate.py

@@ -5281,7 +5281,7 @@ Business Template is a set of definitions, such as skins, portal types and categ
         # override update_catalog parameter only if value
         # is not explicitely passed.
         update_catalog = 1
-      else:
+      elif update_catalog is _MARKER:
         update_catalog = 0
       if update_catalog:
         catalog = _getCatalogValue(self)