Render Drydock logs in text from "bin/drydock lease"; in HTML in web views

Summary: Ref T13073. The new log output from bin/drydock lease currently uses HTML handle rendering, but should render to text.

Test Plan: Ran bin/drydock lease and saw normal text in log output. Viewed the same logs from the web UI and saw HTML.

Subscribers: PHID-OPKG-gm6ozazyms6q6i22gyam

Maniphest Tasks: T13073

Differential Revision: https://secure.phabricator.com/D19101