Custom OpenAI integration: logs

[smkrv]

I found another error with the custom OpenAI integration: if there are multiple, the logs always write the data of the first one created.

And also: if you specify: https://%full_path_url%, the /v1 is still added, so it is correct to specify only the host with the protocol and port. This may be a feature, but I thought I would mention it.

[valentinfrlch]

As suggested in #64, I am going to implement the python openai library instead of using http requests directly. This should also fix this issue. It might take a while though, as I am rewriting the entire request_handlers atm.