Close redundant paths more often

[flub]

The time at which close_redundant_paths is called is a bit tight for all the state machines. We need to check we're actually closing these paths correctly and figure out how to sequence it correctly. This might involve calling it on a timer or something.

[matheus23]

This TODO was removed in this PR. So can we close this?

[flub]

Yep, that change was sufficient to fix this. I think it was two things:

• The rtt is now correct from the start
• The holepunching now happens on the events, but uses all addrs quinn knows at that time. And slow-delivery of events no longer results in stray re-holepunching.