mwqa-cloud-slaves scripts does not use some labels by default while provisioning machines

We aimed to create rhel 7.x machine image with use of minimum resources (using m1.micro flavor) that would be running/executing jenkins job itself (initiating machines, pulling from git, etc.) . Such image requires only basic configuration, not usually used jbds label while being provisioned with mwqa-cloud-slaves scripts. So we used empty/no label but no default labels as one would expect from this script were executed. There is the missing use of IMAGE_LABELS env.: https://gitlab.mw.lab.eng.bos.redhat.com/dev-platform/mwqa-cloud-slaves/blob/master/bin/provision.sh#L172.