message: style(http2): format http2 code
diff: @@ -136,7 +136,7 @@ where
  // streaming state, we either finished it
  // somehow, or the remote reset us.
  return Poll::Ready(Err(crate::Error::new_body_write(
  - "send stream capacity unexpectedly closed"
  + "send stream capacity unexpectedly closed",
  )));
  }
  }
  