Genesis import fails for expired nodes

[peterjgilbert]

Genesis import fails when the registry contains expired nodes:

level=error module=tendermint/registry caller=genesis.go:83 ts=2020-01-25T22:24:31.352771Z msg="InitChain: failed to register node" err="registry: node expired" node="unsupported value type"
level=error module=abci-mux caller=mux.go:433 ts=2020-01-25T22:24:31.352813Z msg="InitChain: fatal error in application" err="registry: genesis node registration failure: registry: node expired" app=200_registry

This is an issue because nodes are kept in the registry after expiring for the debonding period.

[peterjgilbert]

Example of affected genesis dump attached: questnet-dump.tar.gz

[Yawning]

I just did this in my branch since I'm messing with the registry code anyway.