message: shut down sse event streams gracefully
diff: //! Types and functions used by the http server to manage the event-stream.
  use datasize::DataSize;
  -use futures::{Stream, StreamExt};
  +use futures::{future, Stream, StreamExt};
  use http::status::StatusCode;
  use hyper::Body;
  #[cfg(test)]
  @@ -381,6 +381,7 @@ fn stream_to_client(
  }
  }
  })
  + .take_while(|result| future::ready(!matches!(result, Err(RecvError::Closed))))
  }
  #[cfg(test)]
  