Fix restore crash bug
Fix restore crash bug

(cherry picked from commit 852f0d3491e0ecfa5825edc735d1593fea930ef2)

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