Use noreferrer
Use noreferrer

We should use `noreferrer` everywhere when linking to other domains as they otherwise get the referrer and also could redirect the previously opened tab using JS.
owncloud/owncloud.org,lefherz/owncloud.org,LukasReschke/www,LukasReschke/www,owncloud/owncloud.org,owncloud/owncloud.org,lefherz/owncloud.org