Revert "Drop era metadata snap when resetting CBT"
Revert "Drop era metadata snap when resetting CBT"

This reverts commit e5164bcf99e842613d9c1de4de7961a2b5a59c4e.

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