CBQE-0: fix ui tests

not all versions of couchbase have agree checkboxes while initializing

Change-Id: Ideaaa0c356dfa2adac9dfefb02eca0399499b294
Reviewed-on: http://review.couchbase.org/26741
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>