Configure your signing cert in Firefox, (unusually) don't trust the CA
that you would use to issue your signing cert, try to sign a document,
error.
This is reportedly wrong since commit
bfd479abf0 (Update libxmlsec to 1.3.1,
2023-06-09), for some reason our usage of libxmlsec-1.2 didn't trigger
this problem.
Given that we already disable libxmlsec-side cert verify while
verifying a signature (and have our own logic there), it's consistent to
do the same while creating the signature, and that fixes the bug, too.
The Windows / MSCNG backend is not yet changed here.
Change-Id: I8a7adf06b9a26731f1a180a4f6257317084e414a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/180844
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
1817760f56