fixup! NXD Teach GitLab about patches

Upstream changed and simplified UrlBuilder interface:

See:

    - 02cfbf0d (Refactor and expose only Gitlab::UrlBuilder.build(record)
    - https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3696

app/models/merge_request.rb

@@ -443,7 +443,7 @@ class MergeRequest < ActiveRecord::Base
     message << "\n\n"
     message << description.to_s
     message << "\n\n"  if !description.to_s.empty?
-    message << "/reviewed-on #{Gitlab::UrlBuilder.new(:merge_request).build(id)}"
+    message << "/reviewed-on #{Gitlab::UrlBuilder.build(self)}"
     message
   end