verify time validity only with --cert-verify=1

[hnimminh]

Hi @miconda thank again for your useful stuff,

When I run below command to verify time validity:
secsipidx -check -fidentity libre.identity -fpubkey libre.cer -expire 1000000 -ca-file rootca.cer --crl-file crl --cert-verify 1

then output

error message: x509: “SHAKEN FRTE00” certificate is not trusted
not-ok

This error happen because of later validation

Since README document mention

• 1 (1<<0) - verify time validity (not expired and not before validity date)

In my opinion, this error should not happen, cause user only want to verify time validity

So, I created simple pull request for correct it as document, could you please take time to review. Thanks.

[miconda]

The scope was to verify the certificate with or without checking the time validity, but I see what you aim at, might be useful in some cases. I will think about and see what is the best way to get it in. Thanks for the PR!

[miconda]

I pushed a different commit with a new dedicated option (32) for time only verification.