R1:8eb404aea781

Avoid HTML escaping in plain text e-mails

Summary: Seen in e-mail from T2016.

Test Plan: None.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2432

Differential Revision: https://secure.phabricator.com/D5016