Bug 3816: SSL_get_certificate call inside Ssl::verifySslCertificate crashes squid...

Bug 3816: SSL_get_certificate call inside Ssl::verifySslCertificate crashes squid, part2

This patch try to avoid using the SSL_get_certificate function. While configures
squid run tests:
  - to examine if the workaround code can be used
  - to detect buggy SSL_get_certificate

Inside Ssl::verifySslCertificate try to use workarround code and if this is not
possible uses the SSL_get_certificate if it is not buggy, else hit an assertion

This is a Measurement Factory project