* lib/webrick/https.rb (HTTPRequest#meta_vars): create
SSL_CLIENT_CERT_CHAIN_n from @client_cert_chain.
* ext/openssl/ossl_ssl.c (ossl_ssl_get_peer_cert_chain): return nil
if no cert-chain was given.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4897 b2dd03c8-39d4-4d8f-98ff-823fe69b080e