Optimizing jars without preloading/reordering data only moves the
jar central directory to the beginning of the file, which, without
preloading information, is not very useful. Let's just stop doing it if
there's not going to be preloading/reordering information at all.
Differential Revision: https://phabricator.services.mozilla.com/D21170
--HG--
extra : moz-landing-system : lando