This should prevent from restoring from incomplete backups.
Add `-skipBackupCompleteCheck` command-line flag to `vmrestore` in order to be able restoring from old backups without `backup complete` file.
This fixes an issue when VictoriaMetrics doesn't see the restored data after the following operations:
1. Stop VictoriaMetrics.
2. Delete `<-storageDataPath>` dir.
3. Start VictoriaMetrics, then stop it.
4. Restore data from backup with `vmrestore`.
5. Start VictoriaMetrics.
`vmrestore` didn't delete properly empty dirs in `<-storageDataPath>/indexdb` because of the remaining `flock.lock` files in these dirs.