fix copy paste bug to set max non-io at runtime

Change-Id: I097e5fc5d926387dff8874427d373e41e383f64e
Reviewed-on: http://review.couchbase.org/40317
Tested-by: Sundararaman Sridharan <sundar@couchbase.com>
Reviewed-by: Chiyoung Seo <chiyoung@couchbase.com>