qa_crowbarsetup.sh: Only set intended roles for SLES12 nodes on Cloud 5
qa_crowbarsetup.sh: Only set intended roles for SLES12 nodes on Cloud 5

On Cloud 6, all nodes are SLES 12 by default, so we don't want to
restrict compute roles to only one node.

SUSE-Cloud/automation,vmoravec/automation,gosipyan/automation,aspiers/automation,vmoravec/automation,gosipyan/automation,aspiers/automation,vmoravec/automation,aspiers/automation,SUSE-Cloud/automation,vmoravec/automation,SUSE-Cloud/automation,gosipyan/automation,gosipyan/automation,SUSE-Cloud/automation,aspiers/automation