update certificates

[ahorek]

• the certificate from test fixtures is too short and considered insecure on new rubies, so just generate a more secure one
  fixes SSLtest fails only on Ubuntu 20.04 (focal) #359
• use localhost instead of 127.0.0.1, because tests shouldn't depend on IPv4 protocol

[tnir]

Thanks. I tried to use a new certificate with valid notBefore/notAfter signed with the original 1024-bit key, so could not fix it on my local 😁

[tnir]

@tomlea Thoughts?

[tnir]

@rikas Could you merge this PR in advance to merged #366? Or choose someone else in charge of this?

[rikas]

@tnir I'm not very good with certificates and encryption stuff so I don't know exactly what implications this might have. I would prefer to not do it myself without the review of @sonots or @reggieb.

Tom Lea, the original maintainer is not around anymore. I hope one of the above will be... otherwise I'll do it myself.

[reggieb]

Looks good to me.

[rikas]

Ok, I'll merge then! This is from almost a year ago. PRs are taking a very long time to be merged due to inactivity 😞

[tnir]

Thanks @rikas and @reggieb!

[rikas]

Thanks for pushing this forward @tnir 👍