fix for [#25200](https://trac.torproject.org/projects/tor/ticket/25200) ([diff](https://trac.torproject.org/projects/tor/wiki/doc/TorRelaySecurity/OfflineKeys?action=diff&version=20)) URL: https://trac.torproject.org/projects/tor/wiki/doc/TorRelaySecurity/OfflineKeys?version=20