Webfetcher throws error if the content is a .json document.

<img width="525" alt="image" src="https://github.com/Stevenic/vectra/assets/115390646/c0e7aad3-5fc9-4739-8c85-5ef09b664b76">

I'm using the vectra CLI to fetch and index a file (the `tsconfig.json`) from a url. 