Fix for GT Images

includes/helpers.php

@@ -155,7 +155,7 @@ function get_first_existing_file($paths, $referrer = "", $agent = "")
 						array(
 							'http' => array(
 								'method' => 'GET',
-								'user_agent' => 'Mozilla/5.0 (Windows NT 10.0; WOW64; rv:51.0) Gecko/20100101 Firefox/51.0'
+								'user_agent' => $agent
 							)
 						)
 					);