webrick.

* test/webrick/test_httpproxy.rb, test/webrick/test_httpauth.rb,
  test/webrick/test_cgi.rb, test/webrick/test_httpserver.rb,
  test/webrick/test_server.rb, test/webrick/test_filehandler.rb: use
  webrick log as an assertion message.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@20023 b2dd03c8-39d4-4d8f-98ff-823fe69b080e