Re-enrollment looks a little amiss

[directionless]

While debugging something unrelated, I noticed that if the server sends down node_invalid: true we don't appear to correctly handle it.

# From Launcher
{"jsonrpc":"","method":"RequestEnrollment","params":{"enroll_secret":... }

# From K2
{"jsonrpc":"2.0","id":1,"result":{"node_key":"nababe::...","node_invalid":false,"err":null}}

# From Launcher
{"jsonrpc":"","method":"RequestQueries","params":{"node_key":"nababe::..."},"id":1}

# From K2
{"jsonrpc":"2.0","id":1,"result":{"node_invalid":true}}

Then it loops. Notable here, is that there is no RequestEnrollment

(I should fix this as part of my enrollment changes in flight)