noauth: only set token_info if set
noauth: only set token_info if set

Only add the token_info to the keystone headers if it is set.
This resolves an issue which breaks the catalog for some previous
deployments using noauth middleware (the old TripleO undercloud
deploy architecture).

Change-Id: I74d0f71149014418db3af226b419eb7a9cb5bb1e
Closes-bug: #1730280

noironetworks/heat,noironetworks/heat,openstack/heat,openstack/heat