Subject: [Acme] Revert "suggest using DNS over TCP" #137

From: Jacob Hoffman-Andrews <[email-masked]>
Date: Thu, 9 Jun 2016 09:54:35 -0700

https://github.com/ietf-wg-acme/acme/pull/137

This reverts commit 556ab4e (pull #75).

Deployment experience has shown that DNS via TCP to remote hosts is too
unreliable to use in practice. Let's Encrypt uses DNS via TCP only
within its own datacenter, and may stop doing that soon too.