message: refactor(http2): replace server Unpin impl with pin_project
diff: @@ -17,6 +17,7 @@ use super::{PipeToSendStream, SendBuf};
  use crate::{Body, Response};
  +#[pin_project]
  pub(crate) struct Server<T, S, B, E>
  where
  S: HttpService<Body>,
  @@ -27,9 +28,6 @@ where
  state: State<T, B>,
  }
  -// TODO: fix me
  -impl<T, S: HttpService<Body>, B: Payload, E> Unpin for Server<T, S, B, E> {}
  -
  enum State<T, B>
  where
  B: Payload,
  @@ -221,8 +219,6 @@ where
  impl<F, B> H2Stream<F, B>
  where
  - //F: Future<Item=Response<B>>,
  - //F::Error: Into<Box<dyn StdError + Send + Sync>>,
  B: Payload,
  {
  fn new(fut: F, respond: SendResponse<SendBuf<B::Data>>) -> H2Stream<F, B> {
  