fix for azure open ai not returning content sometimes for the when stopping.

[venatir]

When making hundreds of async calls to azure openai, sometimes the response is missing content. {"finish_reason":"stop", ...} This happens in _create_chat_result(). From here _convert_dict_to_message() is called and _dict["content"] is accessed. This leads to very long chain crashing. This error is not caught by any retry mechanism.

[hwchase17]

hmmm do we know why the response is missing content?

[venatir]

hmmm do we know why the response is missing content?

not really. It happens rarely.

[baskaryan]

believe this has been fixed