Avoid deprecation messages when sending an email with PHP 8.2

Fixes #5225

libs/swiftmailer/classes/Swift/NullTransport.php

@@ -18,7 +18,7 @@ class Swift_NullTransport extends Swift_Transport_NullTransport
     public function __construct()
     {
         call_user_func_array(
-            array($this, 'Swift_Transport_NullTransport::__construct'),
+            'Swift_Transport_NullTransport::__construct',
             Swift_DependencyContainer::getInstance()
                 ->createDependenciesFor('transport.null')
         );