Summary:
See <https://discourse.phabricator-community.org/t/commit-6011085b0fcd-breaks-sending-certain-email/1571>. Some mailers get upset if we `setHTMLBody(...)` with an empty string.
There's some possible argument they should be more graceful about this, but it's reasonably pretty ambiguous.
Only try to set the HTML body if we actually have a nonempty HTML body.
Test Plan:
- Configured an "smtp" mailer.
- Ran `echo hi | ./bin/mail send-test --to someone@somewhere.com --subject test`.
- Before: error about empty message body.
- After: no more message body error.
Reviewers: amckinley
Reviewed By: amckinley
Differential Revision: https://secure.phabricator.com/D19494
a7c681b549