skip old OpenSSL

* test/open-uri/test_ssl.rb, test/webrick/test_httpproxy.rb: also
  depends on test/openssl/utils.rb.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48825 b2dd03c8-39d4-4d8f-98ff-823fe69b080e