set the default last_id to 0 to make sure ID are generated from 1

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@19371 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/PropertySheet/Folder.py

@@ -42,7 +42,7 @@ class Folder:
         {   'id'          : 'last_id',
             'description' : 'The default ID group for objects in this folder',
             'type'        : 'string',
-            'default'     : '1',
+            'default'     : '0',
             'mode'        : 'w'},
         {   'id'          : 'id_generator',
             'description' : 'The name of the function to use to generate the Id of a new contained object. Default behaviour (when this value is not set or the function cannot be found) is to increment last_id and update it.',