CBQE-0: fail if not enough VMs in ini

Change-Id: If82f879f6d31556f61dd9cae5837d92086ee4692
Reviewed-on: http://review.couchbase.org/28290
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>