Fix to unit test failure: test_item_pager

Change-Id: I186e6d631ff6723fbb2833cff450e9fceaa69037
Reviewed-on: http://review.couchbase.org/40081
Reviewed-by: Sundararaman Sridharan <sundar@couchbase.com>
Tested-by: abhinav dangeti <abhinav@couchbase.com>