This breaks our tests a bit, which assumed we can always see ourselves
even if we don't have a proper channel.
Usually we would deprecate this first, but it's unlikely to break
anyone since it's a bit obscure that this worked at all.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Changed: JSON-RPC: `listnodes` no longer shows private (peer) nodes: use listpeers