Fix gitlab pages cache config

Merged Nick Thomas requested to merge fix-gitlab-pages-cache-config into master

The current Gitlab Pages NGINX configuration is broken for GitLab Pages v0.5.0+

Pages specifies a Cache-Control header, which NGINX tries to respect, but the default proxy_cache_key value is unsuitable as it doesn't take hostname into account. So, and are both cached under the same key.

We didn't expect NGINX to be caching this data, and it adds no value, so disable it.

This should be picked into %9.5


Edited by Nick Thomas