message: readme: quick typo fix
  Fixes a small typo that inverts the intended meaning.
diff: @@ -245,7 +245,7 @@ async fn write(stream: &mut TcpStream) -> io::Result<usize> {
  Under the hood, the `#[instrument]` macro performs same the explicit span
  attachment that `Future::instrument` does.
  -Note: the [`#[tracing::instrument]`](https://github.com/tokio-rs/tracing/issues/399)` macro does work correctly with the [async-trait](https://github.com/dtolnay/async-trait) crate. This bug is tracked in [#399](https://github.com/tokio-rs/tracing/issues/399).
  +Note: the [`#[tracing::instrument]`](https://github.com/tokio-rs/tracing/issues/399)` macro does not work correctly with the [async-trait](https://github.com/dtolnay/async-trait) crate. This bug is tracked in [#399](https://github.com/tokio-rs/tracing/issues/399).
  ## Getting Help
  