Bump to v2.4.1

Summary: as above

Test Plan: read

Author: Luca Bruno

src/FacebookAds/Api.php

@@ -35,7 +35,7 @@ class Api {
   /**
    * @var string
    */
-  const VERSION = '2.4.0';
+  const VERSION = '2.4.1';
 
   /**
    * @var Api