disable LP_STATS by default

they take forever, so make people turn them on if they want them

Change-Id: I9321a0f1285248f3a9e9894f79fd72a232621fab
Reviewed-on: https://review.openstack.org/31246
Approved: Monty Taylor <mordred@inaugust.com>
Reviewed-by: Monty Taylor <mordred@inaugust.com>
Tested-by: Jenkins