Merge branch 'update_ssl_ciphers' into 'master'

Update ssl ciphers

Removing all DHE suites from Nginx template SSL ciphers.

This will deny forward secrecy for Android 2.3.7, Java 6 and OpenSSL 0.9.8. but will give A+ rating on SSL labs.

Google sites also do not have DHE suites, [source](https://community.qualys.com/blogs/securitylabs/2013/06/25/ssl-labs-deploying-forward-secrecy)

> Google's sites, for example, tend to not have any DHE suites in their configuration. [2013]

See merge request !814

CHANGELOG

@@ -4,6 +4,7 @@ v 7.13.0 (unreleased)
   - Remove project visibility icons from dashboard projects list
   - Rename "Design" profile settings page to "Preferences".
   - Allow users to customize their default Dashboard page.
+  - Update ssl_ciphers in Nginx example to remove DHE settings. This will deny forward secrecy for Android 2.3.7, Java 6 and OpenSSL 0.9.8
 
 v 7.12.0 (unreleased)
   - Fix post-receive errors on a push when an external issue tracker is configured (Stan Hu)

lib/support/nginx/gitlab-ssl

@@ -73,7 +73,7 @@ server {
   ssl_certificate_key /etc/nginx/ssl/gitlab.key;
 
   # GitLab needs backwards compatible ciphers to retain compatibility with Java IDEs
-  ssl_ciphers "ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA:ECDHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES256-GCM-SHA384:AES128-GCM-SHA256:AES256-SHA256:AES128-SHA256:AES256-SHA:AES128-SHA:DES-CBC3-SHA:HIGH:!aNULL:!eNULL:!EXPORT:!DES:!MD5:!PSK:!RC4";
+  ssl_ciphers "ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA:ECDHE-RSA-AES128-SHA:ECDHE-RSA-DES-CBC3-SHA:AES256-GCM-SHA384:AES128-GCM-SHA256:AES256-SHA256:AES128-SHA256:AES256-SHA:AES128-SHA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!MD5:!PSK:!RC4";
   ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
   ssl_prefer_server_ciphers on;
   ssl_session_cache shared:SSL:10m;