Add SettingsController cache reset to integration tests

[MAILPOET-1757]

tests/integration/Cron/Workers/SendingQueue/SendingQueueTest.php

@@ -41,6 +41,7 @@ class SendingQueueTest extends \MailPoetTest {
   private $stats_notifications_worker;
 
   function _before() {
+    parent::_before();
     $wp_users = get_users();
     wp_set_current_user($wp_users[0]->ID);
     $populator = new Populator();