The Resolve Templates button on the New Host form seems broken for image-based provisioning. Steps:

1) Ensure an OS has finish templates for ssh-based provisioning
2) Create a new image-based host
3) Select the OS from (1)
4) Click Resolve Templates - error stack in production.log
5) Provision anyway, confirm template is actually selected and applied

Seen in libvirt but from IRC i believe other CRs are affected. Setting this for 1.16 if we can fix it in time.