Rudder

When users have a free25 license, there is no need for license in generated promises
Plus, the license file doesn't need anymore to lie in the generated promises, it can either be in /var/cfengine/license.dat , or installed with cf-key --install-license on the hub

Nodes don't need license anymore at all on node since 3.6

So:
- copy of licence file should never report error
- only policy server need licence

It would probably even be better if license where manually installed on relay/hub