erp5_web_renderjs_ui: Ensure that came_from is html quoted before redirect

   Without this the redirection places value unquoted causing parser to fail
   later on when resolve {n.me}.

   came_from cannot be None so we simplify the block a bit.

bt5/erp5_web_renderjs_ui/SkinTemplateItem/portal_skins/erp5_web_renderjs_ui/WebSite_login.py

 REQUEST = context.REQUEST
 RESPONSE = REQUEST.RESPONSE
+from ZTUtils import make_query
 
 portal = context.getPortalObject()
 
@@ -26,8 +27,11 @@ if (portal.portal_membership.isAnonymousUser()):
   else:
     message = context.Base_translateString('Login and/or password is incorrect.')
 
-  url = '%s/login_form?portal_status_message=%s' % (context.absolute_url(), message)
-  url = came_from and '%s&came_from=%s' % (url, came_from) or url
+  query_dict = {
+    'portal_status_message': message,
+    'came_from' : came_from
+  }
+  url = '%s/login_form?%s' % (context.absolute_url(), make_query(query_dict))
   RESPONSE.redirect(url)
 else:
   # XXX How to warn user that password will expire?