test certificates in tests/testpkcs11-certs have expired

Description of problem:

test certificates in tests/testpkcs11-certs have expired

Version of gnutls used:

Any released up to 3.7.0

Distributor of gnutls (e.g., Ubuntu, Fedora, RHEL)

All ceritifcates in that directory have expired at same time:

Not After : Dec 13 08:24:54 2020 GMT

How reproducible:

Steps to Reproduce:

• build gnutls
• try to run tests

Actual results:

FAIL: testpkcs11.sh

Expected results:

Success.