When administrators revoke SSH keys, don't include a "security warning" in the mail
Currently, this warning is also shown for revocations with bin/auth revoke --type ssh. However, these revocations are safe (revocations are generally not dangerous anyway) and almost certainly legitimate and administrative, so don't warn users about them.
- Created and revoked a key.
- Creation mail still had warning; revocation mail no longer did.
Reviewed By: amckinley
Maniphest Tasks: T13043
Differential Revision: https://secure.phabricator.com/D18907