Fix tempest configuration on qa_openstack
Fix tempest configuration on qa_openstack

The ssh user used by tempest should be configured on the validatioin
section. Remove values not used by tempest.

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