Zuul change I6d7e7e7a9e19d46a744f9ffac8d532fc6b4bba01 introduced a
multi-line formatter that makes exceptions and other multi-line output
much easier to follow in the logs. Use it here for the simple
formatter in the production Zuul deployment.
Change-Id: I9a8aad8a90f5f4080cdb872d0ed65697a180f57c
2e261fdc42