message: refactor(http): reduce complexity of determing an Encoder
diff: @@ -94,14 +94,11 @@ impl Http1Transaction for ServerTransaction {
  head.headers.set(header::Date(SystemTime::now().into()));
  }
  - let mut is_chunked = true;
  - let mut body = Encoder::chunked();
  - if let Some(cl) = head.headers.get::<header::ContentLength>() {
  - body = Encoder::length(**cl);
  - is_chunked = false
  - }
  + let len = head.headers.get::<header::ContentLength>().map(|n| **n);
  - if is_chunked {
  + let body = if let Some(len) = len {
  + Encoder::length(len)
  + } else {
  let encodings = match head.headers.get_mut::<header::TransferEncoding>() {
  Some(&mut header::TransferEncoding(ref mut encodings)) => {
  if encodings.last() != Some(&header::Encoding::Chunked) {
  @@ -115,7 +112,8 @@ impl Http1Transaction for ServerTransaction {
  if encodings {
  head.headers.set(header::TransferEncoding(vec![header::Encoding::Chunked]));
  }
  - }
  + Encoder::chunked()
  + };
  let init_cap = 30 + head.headers.len() * AVERAGE_HEADER_SIZE;
  