Don't keep re-dialing the same peer

[willscott]

There's a TODO that should be addressed where it isn't particularly useful to re-attempt to learn autonat status from a peer if we've recently asked them.

There are two parts of this:

• if we've asked all of our connected peers recently, we might want to reach an end state faster
• if we have many peers, we should de-prioritize those we've previously asked recently.

[willscott]

should be addressed now in #65

[marten-seemann]

@willscott Did #65 completely address this? Can we close this issue, or is there anything left to do?

[willscott]

Yes. I think it's fair to close this issue as obsolete