The version 2.x.x of PHP HTTP extension is totally different from it’s version 1.x. And it’s not backward compatible at all. So, if you have updated the http extension or installed updated version, you may see it’s not working in previously working source.
So, what to do now? The important thing to note is, http://php.net/http has the documentation for older version (version 1.x.x). Here are 2 links that can help you to quickly start the using new version or to fix your old code.