Fixed cpu draining with parallel requests

Why not add that call so it stops the loop if curl is not ready? That way the loop won't take all the available cpu.

src/Curl/Curl.php

@@ -88,6 +88,7 @@ class Curl
             }
 
             do {
+                curl_multi_select($curl_multi);
                 $status = curl_multi_exec($curl_multi, $active);
             } while ($status === CURLM_CALL_MULTI_PERFORM || $active);