Groq streaming doesn't work with Langchain4J

[stephanj]

This is most likely a bug in Langchain4J...

[stephanj]

It gives a NPE on response.content() in InternalOpenAiHelper

    static Response<AiMessage> removeTokenUsage(Response<AiMessage> response) {
        return Response.from(response.content(), null, response.finishReason());
    }