CBQE-0:fix error message for ui

Change-Id: I07c5a1b2793bf750929d195ddeed6ad7b55ba92f
Reviewed-on: http://review.couchbase.org/31621
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>