message: Fix tests with `url` crate update
  Works around servo/rust-url#577
diff: @@ -39,7 +39,9 @@ impl CanonicalUrl {
  // almost certainly not using the same case conversion rules that GitHub
  // does. (See issue #84)
  if url.host_str() == Some("github.com") {
  - url.set_scheme("https").unwrap();
  + url = format!("https{}", &url[url::Position::AfterScheme..])
  + .parse()
  + .unwrap();
  let path = url.path().to_lowercase();
  url.set_path(&path);
  }
  