core: fix Folder_cut to check relations of sub-objects

This `o` was an unused variable. The initial intention was probably
this.

product/ERP5/bootstrap/erp5_core/SkinTemplateItem/portal_skins/erp5_core/Folder_cut.py

@@ -4,8 +4,8 @@ Base_translateString = portal.Base_translateString
 def Object_hasRelation(obj):
   # Check if there is some related objets.
   result = 0
-  for o in obj.getIndexableChildValueList():
-    for related in obj.portal_categories.getRelatedValueList(obj):
+  for sub_obj in obj.getIndexableChildValueList():
+    for related in obj.portal_categories.getRelatedValueList(sub_obj):
       if related.getRelativeUrl().startswith(obj.getRelativeUrl()):
         continue
       elif related.getRelativeUrl().startswith('portal_simulation') :

[Jérome Perrin]

I looked a bit more at the history of this code:

This code was added in 5d08412f which was at the time same as Folder_delete (with the same unused variable).

Then Folder_delete was changed ( in a6ec9f69 ) to getRelationCountForDeletion. I'll see if we can use getRelationCountForDeletion here as well instead.