The idle period is set to 5sec.
We now also ping every second since last activity.
This makes the quic.Connection less prone to being closed with
no network activity, since we send multiple pings per idle
period, and thus a single packet loss cannot cause the problem.
Errors that are non-recoverable can lead to one of two things happening:
1. That connection lying dead and cloudflared not retrying to make that
connection.
2. cloudflared resolving to a different edge addr to retry connection.
We should subject these errors to a backoff as well. This will result in
us introducing a backoff for 1. When we are going to let the connection
become stale anyway and 2. When we are about to try a different edge
addr.
Nuno Diegues
Devin Carr
Sudarsan Reddy
João Oliveirinha
cthuang