Open Externallink in new Tab

The link to the backup documentation was opened in the active tab.
With this change it will open in a new tab and prevent tabnabbing

src/static/templates/admin/settings.hbs

@@ -122,7 +122,7 @@
                             This does not include any configuration or file attachment data that may
                             also be needed to fully restore a vaultwarden instance. For details on
                             how to perform complete backups, refer to the wiki page on
-                            <a href="https://github.com/dani-garcia/vaultwarden/wiki/Backing-up-your-vault">backups</a>.
+                            <a href="https://github.com/dani-garcia/vaultwarden/wiki/Backing-up-your-vault" target="_blank" rel="noopener noreferrer">backups</a>.
                         </div>
                         <button type="button" class="btn btn-primary" onclick="backupDatabase();">Backup Database</button>
                     </div>