clouddata: use $ibs_source in more places
clouddata: use $ibs_source in more places

to make the provo mirror waste less bandwidth
and the nue mirror a bit more efficient

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