use rangedelete for DL6 test
use rangedelete for DL6 test

Change-Id: I9b99d286d713f5497e3e215dcdd7cddfdd789e05
Reviewed-on: http://review.couchbase.org/61280
Reviewed-by: Wayne Siu <b9526479d8e75eec48092197447318d86d2194ec@couchbase.com>
Tested-by: Wayne Siu <b9526479d8e75eec48092197447318d86d2194ec@couchbase.com>

EricACooper/perfrunner,EricACooper/perfrunner,pavel-paulau/perfrunner,couchbase/perfrunner,couchbase/perfrunner,pavel-paulau/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,pavel-paulau/perfrunner,pavel-paulau/perfrunner,EricACooper/perfrunner,pavel-paulau/perfrunner,couchbase/perfrunner,EricACooper/perfrunner