Use move-back instead of copy-back.
Use move-back instead of copy-back.

To avoid requiring 2x disk space upon restore.

Signed-off-by: Anthony Yeh <1cdc736ba6fd89dd9b69239aea62ddb9fd1482b1@planetscale.com>

tinyspeck/vitess,mahak/vitess,vitessio/vitess,vitessio/vitess,tinyspeck/vitess,vitessio/vitess,mahak/vitess,vitessio/vitess,mahak/vitess,vitessio/vitess,vitessio/vitess,tinyspeck/vitess,mahak/vitess,tinyspeck/vitess,tinyspeck/vitess,mahak/vitess,tinyspeck/vitess,mahak/vitess,mahak/vitess,vitessio/vitess,mahak/vitess,vitessio/vitess,tinyspeck/vitess