found bug

static void sync_tuple_changed_callback(const uint32_t key, const Tuple* new_tuple, const Tuple* old_tuple, void* context) {
  (void) old_tuple;

  switch (key) {
  case SPEED_TEXT:
    strncpy(s_data.speed, s_data.distance, 16); // test code, setting to new_tuple->value->cstring crashes with android
    break;
  case DISTANCE_TEXT:
    strncpy(s_data.distance, new_tuple->value->cstring, 16);
    break;
  case AVGSPEED_TEXT:
    strncpy(s_data.avgspeed, new_tuple->value->cstring, 16);
    break;
  default:
    return;
  }

}

Signed-off-by: Nicholas Jackson <nic@thatlondon.com>