message: docs(body) fix doctest failing due to missing features
  The doctest uses `hyper::Client`, but that is not available unless these features are enabled.
  This commit adds an attribute to check for those and allows `cargo test` with no arguments to pass again.
  fixes
diff: @@ -17,6 +17,7 @@ use super::HttpBody;
  /// # Example
  ///
  /// ```
  +/// # #[cfg(all(feature = "client", any(feature = "http1", feature = "http2")))]
  /// # async fn doc() -> hyper::Result<()> {
  /// use hyper::{body::HttpBody};
  ///
  