certtool cannot extend certs beyond 2049-12-31

While working on reproducible builds for openSUSE, I found that certtool cannot extend certs beyond 2049-12-31

Maybe related to 5b3230ff that says we generate dates with GeneralizedTime format after 2050

Here is a recent example from LibreOffice, but I have seen this problem before with several other certs:

libreoffice-core> certtool -u --load-ca-privkey desktop/qa/data/test-PK-signing.pem  --load-ca-certificate desktop/qa/data/test-cert-chain-1.pem  --load-certificate desktop/qa/data/test-cert-chain-3.pem > x
Generating a signed certificate...
Activation/Expiration time.
The certificate will expire in (days): 11111
set_expiration: ASN1 parser: Element was not found.

The error is probably produced from a src/certtool.c call to gnutls_x509_crt_set_expiration_time