* lib/openssl/ssl.rb: Fix SSL client connection crash for SAN marked
  critical.
  The patch for CVE-2013-4073 caused SSL crash when a SSL server returns
  the certificate that has critical SAN value.  X509 extension could
  include 2 or 3 elements in it:

  [id, criticality, octet_string] if critical,
  [id, octet_string] if not.

  Making sure to pick the last element of X509 extension and use it as
  SAN value.
  [ruby-core:55685] [Bug #8575]

  Thank you @nahi for providing the patch!


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41805 b2dd03c8-39d4-4d8f-98ff-823fe69b080e