MB-8698: Fixed conditional check bug in warmup/loadingAccessLog

When loading access log during warmup, make sure we correctly
check for duplicate items and skip them. The bug caused all
items to be skipped.

Change-Id: I26f4452a9862ea69ab496b3d43758bb824412559
Reviewed-on: http://review.couchbase.org/27685
Reviewed-by: Chiyoung Seo <chiyoung.seo@gmail.com>
Tested-by: Chiyoung Seo <chiyoung.seo@gmail.com>