message: use extend from slice instead of loop
diff: @@ -137,9 +137,7 @@ pub mod cbor {
  pub fn cbor_bs(bs: &[u8], buf: &mut Vec<u8>) {
  write_length_encoding(MajorType::BYTES, bs.len(), buf);
  - for i in 0..bs.len() {
  - buf.push(i as u8);
  - }
  + buf.extend_from_slice(bs)
  }
  pub fn cbor_array_start(nb_elems: usize, buf: &mut Vec<u8>) {
  