Update heat.conf.sample for python-keystoneclient 0.5.0
Update heat.conf.sample for python-keystoneclient 0.5.0

python-keystoneclient 0.5.0 added a new oslo.config option:

 enforce_token_bind=permissive

Change-Id: Icffdef259be276c6c298ad3a5be8aa6c851f49f3

pshchelo/heat,pratikmallya/heat,rdo-management/heat,openstack/heat,maestro-hybrid-cloud/heat,takeshineshiro/heat,steveb/heat,dragorosson/heat,pratikmallya/heat,srznew/heat,ntt-sic/heat,steveb/heat,ntt-sic/heat,openstack/heat,pshchelo/heat,NeCTAR-RC/heat,jasondunsmore/heat,miguelgrinberg/heat,rh-s/heat,jasondunsmore/heat,cryptickp/heat,takeshineshiro/heat,rdo-management/heat,maestro-hybrid-cloud/heat,dims/heat,noironetworks/heat,rh-s/heat,miguelgrinberg/heat,gonzolino/heat,dragorosson/heat,redhat-openstack/heat,NeCTAR-RC/heat,noironetworks/heat,dims/heat,gonzolino/heat,cwolferh/heat-scratch,cryptickp/heat,redhat-openstack/heat,srznew/heat,cwolferh/heat-scratch