#3216 S3v4 storage isn't working sometimes

inc/classes/BxDolStorageS3v4.php

@@ -15,6 +15,7 @@ class BxDolStorageS3v4 extends BxDolStorageS3
 {
     protected function init ($aObject)
     {
+        require_once(BX_DIRECTORY_PATH_PLUGINS . 'amazon-s3/S3.php');
         require_once(BX_DIRECTORY_PATH_PLUGINS . 'amazon-s3/S3v4.php');
         $this->_s3 = new S3v4\S3(
             getParam('sys_storage_s3_access_key'),