add more trailing comma on last array element symfony#9493

Author: pueppiblue

doctrine/pdo_session_storage.rst

@@ -163,7 +163,7 @@ a second array argument to ``PdoSessionHandler``:
                         'db_table' => '%env(SESSIONS_TABLE)%',
                         'db_username' => '%env(MYDATABASE_USERNAME)%',
                         'db_password' => '%env(MYDATABASE_PASSWORD)',
-                    )
+                    ),
                 )
             );