Delay calling _get_user() until AccessKey is created
Delay calling _get_user() until AccessKey is created

Change-Id: I149909d9677f348edd415d3e5f37322b8ad33d28
Fixes: bug #1153397

varunarya10/heat,rickerc/heat_audit,cwolferh/heat-scratch,citrix-openstack-build/heat,pshchelo/heat,steveb/heat,varunarya10/heat,NeCTAR-RC/heat,pratikmallya/heat,takeshineshiro/heat,noironetworks/heat,cryptickp/heat,steveb/heat,miguelgrinberg/heat,JioCloud/heat,rdo-management/heat,jasondunsmore/heat,srznew/heat,ntt-sic/heat,srznew/heat,rickerc/heat_audit,openstack/heat,miguelgrinberg/heat,Triv90/Heat,openstack/heat,jasondunsmore/heat,ntt-sic/heat,redhat-openstack/heat,rh-s/heat,citrix-openstack-build/heat,dragorosson/heat,dims/heat,takeshineshiro/heat,redhat-openstack/heat,gonzolino/heat,maestro-hybrid-cloud/heat,pshchelo/heat,JioCloud/heat,Triv90/Heat,gonzolino/heat,pratikmallya/heat,Triv90/Heat,rdo-management/heat,cwolferh/heat-scratch,maestro-hybrid-cloud/heat,noironetworks/heat,rh-s/heat,dims/heat,cryptickp/heat,NeCTAR-RC/heat,dragorosson/heat