rust: Use a maintained crate for SHA-1 hashing
https://crates.io/crates/rust-crypto hasn’t been updated in 5 years.
This doesn’t neccesarily mean there’s anything wrong with it, but if
something comes up it’s preferable to rely on libraries that have active
maintainers.
Use https://crates.io/crates/sha-1 from https://github.com/RustCrypto instead
Differential Revision: https://phab.mercurial-scm.org/D10835
edition = "2018"
max_width = 79
wrap_comments = true
error_on_line_overflow = true