only add the optiosn if they are not empty

I think this is wrong, but it gets the build passing for now. We should
always add options, but we need to make more guarantees about how the
underlying url helper is called

actionpack/lib/action_dispatch/routing/polymorphic_routes.rb

@@ -135,7 +135,9 @@ def polymorphic_url(record_or_hash_or_array, options = {})
         named_route = build_named_route_call(record_or_hash_or_array, record, inflection, options)
 
         url_options = options.except(:action, :routing_type)
-        args << url_options
+        unless url_options.empty?
+          args << url_options
+        end
 
         args.collect! { |a| convert_to_model(a) }