vcl PDF NSS sign: don't embed signed timestamp to the signature blob

There are several reasons to avoid doing so:

- The mscrypto backend doesn't do that, so the previous situation was
inconsistent.
- PDF provides markup to provide a timestamp, and that's automatically
part of the signed data.
- Page 10 of "PAdES Basic" specification from
<http://www.etsi.org/deliver/etsi_ts%5C102700_102799%5C10277802%5C01.02.01_60%5Cts_10277802v010201p.pdf>
explicitly requests either not writing that data, or writing it as an
unsigned attribute (probably to underline that the value is from untrusted
source, it's the signer's computer clock).

Change-Id: I35b1a9ef4a391a24e6695353d617f27c7d96d93b
Reviewed-on: https://gerrit.libreoffice.org/30926
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Jenkins <ci@libreoffice.org>

0 files changed, 0 insertions, 0 deletions