Support portal_skin parameter (in the same way as the rest of ERP5)

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@25560 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/WebSite.py

@@ -110,7 +110,7 @@ class WebSiteTraversalHook(Persistent):
 
     # If a skin selection is defined in this web site, change the skin now.
     skin_selection_name = container.getSkinSelectionName()
-    if skin_selection_name: # XXX missing support to portal_skin parameter
+    if skin_selection_name and request.get('portal_skin', None) is None:
       container.getPortalObject().changeSkin(skin_selection_name)
 
     # Set default language if any