Manual PDF link on 404 page is a 404 itself

[huonw]

The doc.rust-lang.org 404 page has

• The Rust official site
• The Rust reference manual (* PDF)

with the PDF link directing to http://doc.rust-lang.org/rust.pdf (which is a 404 at the time of writing).

[steveklabnik]

This page now links to http://doc.rust-lang.org/reference.pdf which is also wrong.

What should the link actually be?