Support "ssh-dss" keys

Summary: Ref T4151. These are a (common) variant of "ssh-dsa" keys (which are somewhat theoretical, but show up on Google).

Test Plan: syntax

Reviewers: btrahan, dctrwatson, phpcodemonkey

Reviewed By: phpcodemonkey

CC: aran

Maniphest Tasks: T4151

Differential Revision: https://secure.phabricator.com/D7704

src/applications/settings/panel/PhabricatorSettingsPanelSSHKeys.php

@@ -84,8 +84,11 @@ final class PhabricatorSettingsPanelSSHKeys
 
           $recognized_keys = array(
             'ssh-dsa',
+            'ssh-dss',
             'ssh-rsa',
             'ecdsa-sha2-nistp256',
+            'ecdsa-sha2-nistp384',
+            'ecdsa-sha2-nistp521',
           );
 
           if (!in_array($type, $recognized_keys)) {