message: remove incorrect todo
  I tried repeatedly to remove the Rc with nll on.
  `query` works, but it can not be called repeatedly.
diff: @@ -11,7 +11,6 @@ pub struct RegistryQueryer<'a> {
  pub registry: &'a mut (Registry + 'a),
  replacements: &'a [(PackageIdSpec, Dependency)],
  try_to_use: &'a HashSet<&'a PackageId>,
  - // TODO: with nll the Rc can be removed
  cache: HashMap<Dependency, Rc<Vec<Candidate>>>,
  // If set the list of dependency candidates will be sorted by minimal
  // versions first. That allows `cargo update -Z minimal-versions` which will
  