replication of charts between gpn-tn should not flatten levels

We currently have:

which causes trouble for charts and puts the charts at the top level kubernetes in registry-tn.

We've been doing:

skopeo copy docker://registry-tn.cern.ch/kubernetes/cern-magnum:0.15.0-tn docker://registry-tn.cern.ch/kubernetes/charts/cern-magnum:0.15.0-tn

but the fix should be to change the replication rule to not flatten, or flatten 1.