Nullpointer on every message

[nitram22]

Hello,

I noticed that this Java library stopped working. With every incoming message a null pointer was thrown. A similar issue already existed for this: https://github.com/CaliDog/certstream-java/issues/11

The reason for this is probably that the data structure of the Certstream server has changed, but this library has not been adapted to it.

I have compared which data is sent from the Certstream server and which is parsed here in the POJOs. The field "as_der" is no longer included in the data, but was still included in the POJO. The fields "cert_link", "issuer" and "signature_algorithm" were not included in the POJOs.

I have adjusted the POJOs accordingly so that the library works again:

Are you guys okay with the changes like this? If so, it would be good if you could approve the pull request and build a new release so that the library can be used again.

Best regards

Martin

[tost11]

This pr still solves the parsing errors, at least for me. Thanks! Please merge, so this lib is working again