webrick: filter out HTTP_PROXY for CGIHandler
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55731 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
webrick: filter out HTTP_PROXY for CGIHandler
[ruby-core:76511] [Bug #12610]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55731 b2dd03c8-39d4-4d8f-98ff-823fe69b080e