certutil: only add non-empty DNSNames to certificates

[AndersonQ]

What does this PR do?

Adds an extra check to ensure DNSNames are non-empty

Why is it important?

Certificates DNS names should not be empty. Go introduced an extra check for that in 1.24.8 and later removed on 1.24.9 as it was a breaking change. As CreateCertificate allows for empty DNS names, let's avoid it on our side.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have added tests that prove my fix is effective or that my feature works

Related issues

[elasticmachine]

💚 Build Succeeded

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• Commit: 8ec3750

History

• 💚 Build #859 succeeded 6f40fb5

cc @AndersonQ