message: Improve readbility of enqueue
diff: @@ -81,20 +81,17 @@ fn enqueue<S: Storage, A: Api, Q: Querier>(
  ) -> StdResult<HandleResponse> {
  // find the last element in the queue and extract key
  let last_item = deps.storage.range(None, None, Order::Descending)?.next();
  - let last_key = match last_item {
  - None => None,
  - Some(Err(e)) => return Err(e),
  - Some(Ok((key, _))) => Some(key),
  - };
  - // all keys are one byte
  - let my_key = match last_key {
  - Some(k) => k[0] + 1,
  + let new_key = match last_item {
  None => FIRST_KEY,
  + Some(item) => {
  + let (key, _) = item?;
  + key[0] + 1 // all keys are one byte
  + }
  };
  - let data = to_vec(&Item { value })?;
  + let new_value = to_vec(&Item { value })?;
  - deps.storage.set(&[my_key], &data)?;
  + deps.storage.set(&[new_key], &new_value)?;
  Ok(HandleResponse::default())
  }
  