Use "localhost" for net/http only on Windows where it seems necessary

* On other platforms, 127.0.0.1 is much more reliable and required in some cases.

Author: eregon

spec/ruby/library/net/http/http/fixtures/http_server.rb

@@ -63,8 +63,9 @@ def port
     end
 
     def start_server
+      bind_address = platform_is(:windows) ? "localhost" : "127.0.0.1"
       server_config = {
-        BindAddress: "localhost",
+        BindAddress: bind_address,
         Port: 0,
         Logger: WEBrick::Log.new(NullWriter.new),
         AccessLog: [],