Fix for reconfigure failure when using a non-bundled web-server

When the bundled web server was disabled the ci-proxying recipe failed because it tried to access a non-existent system service. I've switched the reciped to using runit_service instead. The restart is also only triggered if the bundled nginx is actually enabled.

I've also added a spec file for the fix and some helper files from: https://github.com/chef-cookbooks/runit. I think that the license should be ok (Apache 2.0).

I'll be restarting this merge request.