Revert "Merge pull request #1 from cultureamp/PROD-1685-reports-are-unstyled"

This reverts commit 87e67a18057d98214b355648833c01d8c17ab05e, reversing
changes made to f859bb13c7dd464ac351bf6307f24412e3781d39.

Logging wkhtmltopdf output turns out not to provide much useful
information (must be why it's disabled by default).