Fix SSL_get_peer_certificate memory leak

Fix SSL_get_peer_certificate memory leak

The SSL_get_peer_certificate openSSL function increases the lock for X509
object it returns so X509 object retrieved using this function must be
released with X509_free after use.
This patch uses the Ssl::X509_Pointer TidyPointer to release X509 object
retrieved with the SSL_get_peer_certificate function inside the
Ssl::PeerConnector::handleNegotiateError method

This is a Measurement Factory project