Set updated_at if is present in columns.

main/inc/lib/model.lib.php

@@ -193,6 +193,10 @@ class Model
             $params['created_at'] = api_get_utc_datetime();
         }
 
+        if (in_array('updated_at', $this->columns)) {
+            $params['updated_at'] = api_get_utc_datetime();
+        }
+
         if (!empty($params)) {
             $id = Database::insert($this->table, $params, $show_query);
             if (is_numeric($id)) {