Make sure there is never posted data on GET requests

This is an addition to the previous patch to make sure there can not
accidentally $data be passed on a GET request.

darcs-hash:20080331223807-7ad00-0f03763f15a9d907da6a53ed8b3c3e55b906fbc7.gz

inc/HTTPClient.php

@@ -197,6 +197,8 @@ class HTTPClient {
             }
             $headers['Content-Length'] = strlen($data);
             $rmethod = 'POST';
+        }elseif($method == 'GET'){
+            $data = ''; //no data allowed on GET requests
         }
         if($this->user) {
             $headers['Authorization'] = 'Basic '.base64_encode($this->user.':'.$this->pass);