Repo Archive path invalid after rename

[KN4CK3R]

After a repository rename the old archive path gets unaccessable which prevents deleting old archives.
Reason is the repository name in the filepath:
fmt.Sprintf("%s/%s/%s.%s", repo.FullName(), archiver.CommitID[:2], archiver.CommitID, archiver.Type.String())

/cc @lunny