cbqe-0: catch 404 error

Change-Id: Idc5ac2e85972172a76aa6b83825c982d777585b6
Reviewed-on: http://review.couchbase.org/36860
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>