[AC-2097] iOS: Network.HTTPClient is cleaning all request headers

I'm working in a application that have this request:

var xhr = Ti.Network.createHTTPClient();

xhr.setRequestHeader("foo", "bar");
xhr.setRequestHeader("Content-Type", "text/plain");

xhr.open("POST", "http://foo.bar");

xhr.send("Foobar");

But I'm having some problems with it (and other people too: http://developer.appcelerator.com/question/147651/setrequestheader-doesnt-work). In *TiNetworkHTTPClientProxy.m* we have this following statement (line 384):

-(void)open:(id)args
{
   ...
   request = [[ASIFormDataRequest requestWithURL:url] retain];
   ... 
}

I think this is cleaning all headers included in request. Am i correctly? So, I changed the code to (because the request already exists):

[request requestWithURL:url];

And it works fine. If I'm correctly, I will make a PR ASAP to titanium_mobile project.