title: [golang]Is it possible to write TLS server without certificate?
body: <p>From client I already have tls config which sets <code>InsecureSkipVerify</code> to true. How to write server for this client which take any cert.
  Can <code>tls.config</code> help in server too? like setting <code>InsecureSkipVerify</code> to true?</p>