Bug 1571934 - Inline security-prefs.js into all.js. r=keeler

security-prefs.js is #included into greprefs.js, but there's no good reason for
it to be separate from all.js. Having it separate makes it easier to overlook,
and all.js has a bunch of `security.*` prefs in it anyway.

This patch inlines it into all.js. It inlines it at the start of the file to
minimize the risk of the change, so that the prefs end up in greprefs.js in the
same order as before.

Differential Revision: https://phabricator.services.mozilla.com/D40919

--HG--
extra : moz-landing-system : lando