qa_crowbarsetup: cleanup and reorder set_proposalvars
qa_crowbarsetup: cleanup and reorder set_proposalvars

* Default storage is neither ceph nor swift.
* Honour both want_ceph and want_swift variables consistently.
* Reorder code that touches wantswift and wantceph to allow
  sanity check.
* Adding headings for code blocks.

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