unit1399: fix integer overflow

  */

  data.progress.t_startsingle.tv_sec = now.tv_sec - 3;

  data.progress.t_startsingle.tv_usec = now.tv_usec;

  data.progress.t_redirect = (now.tv_sec - 2) * usec_magnitude;

  data.progress.t_redirect = data.progress.t_starttransfer + 1;

  Curl_pgrsTime(&data, TIMER_STARTTRANSFER);