fixed issue with namespace AND fixed issue #649

lib/Cron/Daemon.php

@@ -1,11 +1,9 @@
 <?php
-if(!defined('ABSPATH')) exit;
-
 namespace MailPoet\Cron;
-
 use MailPoet\Cron\Workers\Scheduler as SchedulerWorker;
 use MailPoet\Cron\Workers\SendingQueue\SendingQueue as SendingQueueWorker;
 
+if(!defined('ABSPATH')) exit;
 require_once(ABSPATH . 'wp-includes/pluggable.php');
 
 class Daemon {