bug 1549249 - hard-code new add-on signing intermediate so it's always available r=jcj,kmag a=tomprince
Our previous approach to making this intermediate available relied on being able
to add it to the user's NSS cert DB. This does work in the majority of cases,
but there are some situations where it doesn't work (e.g. if the user's DB is
set to read only, if they've configured Firefox to run in "nocertdb" mode, if
they have a master password but forgot it, and so on). This patch compiles the
intermediate in to Firefox in the same way we incorporate the root, so it should
always be available.
At the same time, this patch reverts the changes from
848b15028562c6757748070f637e0e4f0bbb5f65 (the patch that implemented the
original approach) because it should no longer be necessary.
This also bumps the add-on DB schema to trigger add-on revalidation.
Differential Revision: https://phabricator.services.mozilla.com/D30140
