fixes #1529 rewrite list of filter users for activities

* migration task to update activity.performed_by (with object_id) for logout action (was always user guest instead of the real user)
* activities: use the actual regrouped lines to list filter users (instead of performing a separate SQL query)

install/db/162-database.php

@@ -0,0 +1,25 @@
+<?php
+// +-----------------------------------------------------------------------+
+// | This file is part of Piwigo.                                          |
+// |                                                                       |
+// | For copyright and license information, please view the COPYING.txt    |
+// | file that was distributed with this source code.                      |
+// +-----------------------------------------------------------------------+
+
+if (!defined('PHPWG_ROOT_PATH'))
+{
+  die('Hacking attempt!');
+}
+
+$upgrade_description = 'change activity.performed_by for logout';
+
+$query = '
+UPDATE '.PREFIX_TABLE.'activity
+  SET performed_by = object_id
+  WHERE action = \'logout\'
+;';
+pwg_query($query);
+
+echo "\n".$upgrade_description."\n";
+
+?>