Port 4434 instead of 443

[schoen]

@jking

My understanding is that the initial “challenge” is over port 80, then all other activity, such as a renewal, takes place over port 443. At this point is port 80 still required?

It's possible to renew a certificate with a TLS-SNI-01 validation on port 443, but I'm not sure relying on this can be recommended since the ability to do so was previously described as "temporary":

TLS-SNI challenges disabled for most new issuance

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