Don't update local backup success status on unsuccessfull or image backup without shaodwcopy
Don't update local backup success status on unsuccessfull or image backup without shaodwcopy

(cherry picked from commit 46c56ba20575cb3aa63bb8f9d10b004b4bc16c0a)

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