CBQE-0: fix for index error in update orchestrator

Change-Id: I0b0ca546ef696b28b7f8a73de38b851b719a1f73
Reviewed-on: http://review.couchbase.org/26180
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Tommie McAfee <tommie@couchbase.com>