Add missing header to some files

system/migrate.php

@@ -1,4 +1,13 @@
 <?php
+/**
+ * Database migrations
+ *
+ * @package   MyAAC
+ * @author    Slawkens <slawkens@gmail.com>
+ * @copyright 2019 MyAAC
+ * @link      https://my-aac.org
+ */
+defined('MYAAC') or die('Direct access not allowed!');
 
 // database migrations
 $tmp = '';
@@ -19,4 +28,4 @@ else { // register first version
 		require SYSTEM . 'migrations/' . $i . '.php';
 		updateDatabaseConfig('database_version', $i);
 	}
-}
+}