Fix duplicate LLM_BASE_URL entry in config.toml and enable diff embeddings

[isavita]

Description

This PR resolves the issue of duplicate LLM_BASE_URL entries in config.toml and enhances support for various ollama embeddings.

Subtasks

1. Resolves Issue #1434 from the OpenDevin repository.
2. Extends support for multiple ollama embeddings, further details can be found here.

Testing

I'm currently unsure about the best way to test these changes. I wanted to check for potential crashes by querying embeddings not listed in my ollama ls, but I've been unable to force the use of a specific embedding. Does anyone have suggestions on how to effectively test this? I'm running the project locally using the make setup.