tls: fix check for reused session

When TLS Session Ticket is renewed by server - no Certificate record is
to the client. We are prepared for empty certificate in this case, but
this relies on the session reuse check, which was implemented
incorrectly and was returning false when the TLS Session Ticket was
renewed.

Use session reuse check provided by OpenSSL instead.

Fix: https://github.com/nodejs/io.js/issues/2304
PR-URL: https://github.com/nodejs/io.js/pull/2312


Reviewed-By: Shigeki Ohtsu <ohtsu@iij.ad.jp>