ironore15

### What happened? Using gemini-pro as a litellm proxy is currently impossible. Some `llm_providers` such as `palm`, `gemini`, `vertex_ai` is ignoring the `base_url` argument. https://github.com/BerriAI/litellm/blob/ef4c85522c001c930f02e2ec2c32dea9a7816b74/litellm/main.py#L1629 ### Relevant log output ```shell...