Use 403 for API errors on missing rights

inc/api/api.class.php

@@ -2662,7 +2662,7 @@ abstract class API extends CommonGLPI {
    public function messageRightError($return_error = true) {
 
       $this->returnError(__("You don't have permission to perform this action."),
-                         401,
+                         403,
                          "ERROR_RIGHT_MISSING",
                          false,
                          $return_error);

tests/APIBaseClass.php

@@ -915,7 +915,7 @@ abstract class APIBaseClass extends atoum {
                     'id'       => $tickets_id,
                     'headers'  => [
                         'Session-Token' => $data['session_token']]],
-                   401,
+                   403,
                    'ERROR_RIGHT_MISSING');
 
       // try to access ticket list (we should get empty return)