message: use entry to not hash twice thanks clippy
diff: @@ -138,12 +138,14 @@ fn read_nested_packages(path: &Path,
  let pkg = Package::new(manifest, &manifest_path);
  let pkg_id = pkg.package_id().clone();
  - if !all_packages.contains_key(&pkg_id) {
  - all_packages.insert(pkg_id, pkg);
  - } else {
  + use ::std::collections::hash_map::Entry;
  + match all_packages.entry(pkg_id) {
  + Entry::Vacant(v) => { v.insert(pkg); },
  + Entry::Occupied(_) => {
  info!("skipping nested package `{}` found at `{}`",
  pkg.name(), path.to_string_lossy());
  }
  + }
  // Registry sources are not allowed to have `path=` dependencies because
  // they're all translated to actual registry dependencies.
  