Add negotiated SSL protocol and cipher to Net::HTTP debug output

From: Bart de Water <bartdewater@gmail.com>
https://github.com/ruby/ruby/pull/1877 [Feature #15009]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65233 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/net/http.rb

@@ -997,7 +997,7 @@ module Net   #:nodoc:
         if @ssl_context.verify_mode != OpenSSL::SSL::VERIFY_NONE
           s.post_connection_check(@address)
         end
-        D "SSL established"
+        D "SSL established, protocol: #{s.ssl_version}, cipher: #{s.cipher[0]}"
       end
       @socket = BufferedIO.new(s, read_timeout: @read_timeout,
                                write_timeout: @write_timeout,