Explicitly close the tcp connection.

Without this, the connection will be alive without GC after exit
the block and the test will fail as "TCPServer was closed and SSLServer
is still alive" on 64bit Unix: at least CentOS, Ubuntu, and FreeBSD.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@33300 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/openssl/test_ssl.rb

@@ -212,6 +212,7 @@ tddwpBAEDjcwMzA5NTYzMTU1MzAwpQMCARM=
       ssl.session = session
 
       assert_equal session, ssl.session
+      sock.close
     }
   end