CBQE-0:  revert active resident ratio change

Change-Id: I2a26ecdb5115052d843c5d4dc764a94738b4b831
Reviewed-on: http://review.couchbase.org/40696
Reviewed-by: Parag Agarwal <agarwal.parag@gmail.com>
Tested-by: Parag Agarwal <agarwal.parag@gmail.com>