Remove a very old piece of config documentation

Summary: Ref T571. This was accidentally left behind in D12266.

Test Plan: Used {key command F} to search for "bulk".

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T571

Differential Revision: https://secure.phabricator.com/D17034

src/applications/config/option/PhabricatorMetaMTAConfigOptions.php

@@ -98,16 +98,6 @@ EODOC
 You can disable the "To:" and "Cc:" footers in mail if users prefer smaller
 messages.
 EODOC
-));
-
-    $bulk_description = $this->deformat(pht(<<<EODOC
-If this option is enabled, Phabricator will add a "Precedence: bulk" header to
-transactional mail (e.g., Differential, Maniphest and Herald notifications).
-This may improve the behavior of some auto-responder software and prevent it
-from replying. However, it may also cause deliverability issues -- notably, you
-currently can not send this header via Amazon SES, and enabling this option with
-SES will prevent delivery of any affected mail.
-EODOC
 ));
 
     $email_preferences_description = $this->deformat(pht(<<<EODOC