Remove WP\Functions::__ and other translate functions

Under the new sniffer rules, those functions produce errors and, when those methods
are used, the sniffer can not properly be applied.

[MAILPOET-4524]

mailpoet/lib/Models/SendingQueue.php

@@ -4,7 +4,6 @@ namespace MailPoet\Models;
 
 use MailPoet\Entities\SendingQueueEntity;
 use MailPoet\Util\Helpers;
-use MailPoet\WP\Functions as WPFunctions;
 
 /**
  * @property int $countProcessed
@@ -34,7 +33,7 @@ class SendingQueue extends Model {
     parent::__construct();
 
     $this->addValidations('newsletter_rendered_body', [
-      'validRenderedNewsletterBody' => WPFunctions::get()->__('Rendered newsletter body is invalid!', 'mailpoet'),
+      'validRenderedNewsletterBody' => __('Rendered newsletter body is invalid!', 'mailpoet'),
     ]);
   }