message: Fix call recv_streams.get_mut()
diff: @@ -3121,10 +3121,7 @@ impl Connection {
  /// Returns `InvalidStreamId` if a stream does not exist or the receiving
  /// side is closed.
  pub fn set_stream_max_data(&mut self, stream_id: u64, max_data: u64) -> Res<()> {
  - let stream = self
  - .recv_streams
  - .get_mut(&stream_id.into())
  - .ok_or(Error::InvalidStreamId)?;
  + let stream = self.recv_streams.get_mut(stream_id.into())?;
  stream.set_stream_max_data(max_data);
  Ok(())
  