fix openai api breaking change

[jrpereirajr]

OpenAI API error:

<class 'openai.lib._old_api.APIRemovedInV1'>: You tried to access openai.ChatCompletion, but this is no longer supported in openai>=1.0.0 - see the README at https://github.com/openai/openai-python for the API. You can run openai migrate to automatically upgrade your codebase to use the 1.0.0 interface. Alternatively, you can pin your installation to the old version, e.g. `pip install openai==0.28