use modern, safe and fast ciphers
 Merge branch 'update-ciphers-nginx' into 'master'

Update Ciphers Nginx

The current suggested Ciphers do not qualify anymore as completely safe, see for instance [here.](https://community.qualys.com/blogs/securitylabs/2013/03/19/rc4-in-tls-is-broken-now-what)

This updates the ciphers, following [Remy's advise](https://raymii.org/s/tutorials/Strong_SSL_Security_On_nginx.html).
Merge branch 'master' of github.com:gitlabhq/gitlab-recipes