Disable registry on sidekiq nodes

After https://gitlab.com/gitlab-org/omnibus-gitlab/issues/2558 got merged and deployed we never removed the registry service from sidekiq nodes. According to this we should be doing this.

I gave a quick look at the registry logs on a few sidekiq nodes and I can only see GC operations, nothing else.

We should proceed with this after 10.0 final hits prod.

changed the description

changed milestone to %WoW

changed milestone to %WoW ending 2017-10-03

assigned to @omame

Done.

closed