Add missing MOODLE_INTERNAL constants

classes/core_userkey_manager.php

@@ -24,6 +24,8 @@
 
 namespace auth_userkey;
 
+defined('MOODLE_INTERNAL') || die;
+
 class core_userkey_manager implements userkey_manager_interface {
 
     /**

db/services.php

@@ -22,6 +22,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die;
+
 $functions = array(
     'auth_userkey_request_login_url' => array(
         'classname'   => 'auth_userkey_external',

lang/en/auth_userkey.php

@@ -22,6 +22,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die;
+
 $string['pluginname'] = 'User key authentication';
 $string['auth_userkeydescription'] = 'Log in to Moodle using one time user key.';
 $string['mappingfield'] = 'Mapping field';