rust/chg/build.rs

patchbomb: use procutil.shellquote() instead of shlex to escape email address

This basically backs out 2cc453284d5c, and inserts procutil.shellquote()
instead. I don't care about Windows compatibility here, but shlex.quote()
can't handle byte strings on Python 3.

extern crate cc;

fn main() {
    cc::Build::new()
        .warnings(true)
        .file("src/sendfds.c")
        .file("src/sighandlers.c")
        .compile("procutil");
}