R1:84f94994ad47

Remove "metamta.insecure-auth-with-reply-to" Config option

Summary:
Ref T7477. This option was added in D842 in 2011, to support a specific narrow use case at Quora with community moderators using some kind of weird Gmail config.

I don't recall it ever coming up since then, and a survey of a subset of hosted instances (see T11760) reveals that no instances are using this option today. Presumably, even Quora has completed the onboarding discussed in D842, if they still use Phabricator. This option…