MB-11347 Disable the memory accounting based on new / delete hook

This change disables the memory accounting based on new / delete
hook temporarily until we fix the memory accounting overflow
issue.

Change-Id: I9e4394c06dafd71e4e6e285a0182122334ea4686
Reviewed-on: http://review.couchbase.org/38896
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Chiyoung Seo <chiyoung@couchbase.com>