The NewSessionTicket message is not optional.

Per RFC 4507, section 3.3:

   This message [NewSessionTicket] MUST be sent if the
   server included a SessionTicket extension in the ServerHello.  This
   message MUST NOT be sent if the server did not include a
   SessionTicket extension in the ServerHello.

The presence of the NewSessionTicket message should be determined
entirely from the ServerHello without probing.

RT#4389

Reviewed-by: Emilia Käsper <emilia@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>