Do not retry getting parallel hash after error
Do not retry getting parallel hash after error

(cherry picked from commit 51dca612ba29db37640840e35d9d306b07bc9f26)

uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend