backup: break one key scan when met delete version (#6655)
backup: break one key scan when met delete version (#6655)

Signed-off-by: luancheng <55ec65866f27fbdb3d888d12d8f4cdb1cc125aee@pingcap.com>

pingcap/tikv,BusyJay/tikv,BusyJay/tikv,BusyJay/tikv,pingcap/tikv,c4pt0r/tikv,BusyJay/tikv