message: Use implicit cast
diff: @@ -532,7 +532,7 @@ Commit Repository::lookupCommit(const QString &prefix) const {
  Commit Repository::lookupCommit(const Id &id) const {
  git_commit *commit = nullptr;
  - git_commit_lookup(&commit, d->repo, &id.d);
  + git_commit_lookup(&commit, d->repo, id);
  return Commit(commit);
  }
  