message: Add a link to the Clippy's false positive bug around boxed_local
diff: @@ -19,7 +19,8 @@ trait FnBox<A, R> {
  }
  impl<A, R, F: FnOnce(A) -> R> FnBox<A, R> for F {
  - #[cfg_attr(feature = "cargo-clippy", allow(boxed_local))] // The use of Box is intentional here
  + // False positive: https://github.com/rust-lang-nursery/rust-clippy/issues/1123
  + #[cfg_attr(feature = "cargo-clippy", allow(boxed_local))]
  fn call_box(self: Box<F>, a: A) -> R {
  (*self)(a)
  }
  