CBQE-1378 Fix a typo in conf file

Change-Id: I98b5128de4ac3bd9de6bfdba69237c3a673beb62
Reviewed-on: http://review.couchbase.org/27754
Reviewed-by: Chisheng Hong <chisheng@couchbase.com>
Tested-by: Chisheng Hong <chisheng@couchbase.com>