message: tower-http: Add clone impl for Service and MakeService
diff: @@ -14,7 +14,7 @@ use tokio_trace_futures::{Instrument, Instrumented};
  use tower::MakeService;
  use tower_service::Service;
  -#[derive(Debug)]
  +#[derive(Debug, Clone)]
  pub struct InstrumentedHttpService<T> {
  inner: T,
  span: Option<Span>,
  @@ -33,7 +33,7 @@ impl<T> InstrumentedHttpService<T> {
  }
  }
  -#[derive(Debug)]
  +#[derive(Debug, Clone)]
  pub struct InstrumentedMakeService<T, B> {
  inner: T,
  span: Option<Span>,
  