Even though we detect a Redirect code not always we can rely that server will...

Even though we detect a Redirect code not always we can rely that server will send a correct location header. 
Be more robust and add a basic check. 


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@25868 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Wizard/Tool/WizardTool.py

@@ -354,6 +354,7 @@ class WizardTool(BaseTool):
       if f.code> 300 and f.code <400:
         # adjust return url which my contain proxy URLs as arguments
         location = metadata.getheader('location')
+        if location is not None:
           parsed_url = list(urlparse(location))
           local_site_url_prefix = urllib.quote('%s/portal_wizard/proxy' \
                                                 %self.getPortalObject().absolute_url())