Revert "Added request.Proxy=null everywhere, as discussed in http://stackoverflow.com/questions/2519655/httpwebrequest-is-extremely-slow."

But the patch is here, in case anyone wants to try it.

This reverts commit 531edd51d8.

OpenSim/Framework/Servers/HttpServer/RestObjectPosterResponse.cs

@@ -57,7 +57,6 @@ namespace OpenSim.Framework.Servers.HttpServer
 
             WebRequest request = WebRequest.Create(requestUrl);
             request.Method = verb;
-            request.Proxy = null;
             request.ContentType = "text/xml";
             request.Timeout = 10000;