Compilation fails on osx: libc::sigaction::sa_restorer.

From cargo clippy --all-features --all-targets -- -D warning

error[E0560]: struct `libc::sigaction` has no field named `sa_restorer`
   --> crates/tor-hsservice/src/replay.rs:656:21
    |
656 |                     sa_restorer: None,
    |                     ^^^^^^^^^^^ `libc::sigaction` does not have this field
    |
    = note: all struct fields are already assigned