static void restart_listener_cb(void *user_data)
{
    pjsua_transport_id transport_id = (pjsua_transport_id)(pj_size_t)user_data;
    restart_listener(transport_id, 0);
}
static void restart_listener_cb(void *user_data)
{
    pjsua_transport_id transport_id = (pjsua_transport_id)(pj_size_t)user_data;
    restart_listener(transport_id, 0);
}