message: chore(dependencies): update h2's trailer signature
diff: @@ -309,9 +309,9 @@ impl Payload for Body {
  fn poll_trailers(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Option<Result<HeaderMap, Self::Error>>> {
  match self.kind {
  Kind::H2 { recv: ref mut h2, .. } => match ready!(h2.poll_trailers(cx)) {
  - Some(Ok(t)) => Poll::Ready(Some(Ok(t))),
  - Some(Err(e)) => Poll::Ready(Some(Err(crate::Error::new_h2(e)))),
  - None => Poll::Ready(None),
  + Ok(Some(t)) => Poll::Ready(Some(Ok(t))),
  + Err(e) => Poll::Ready(Some(Err(crate::Error::new_h2(e)))),
  + Ok(None) => Poll::Ready(None),
  },
  _ => Poll::Ready(None),
  }
  