redundant code in `setTime()`

[denis-stepanov]

System::setTime() currently has:

  if (!settimeofday(&tv_new_time, NULL)) {
    time = new_time;
    localtime_r(&time, &tm_time);
    setTimeSyncTime(time);
    setTimeSyncStatus(TIME_SYNC_OK);
  }

At the same time, we set a callback to settimeofday() and that callback does all the same actions. So it is not necessary to make them in setTime().