static-web-apps-deploy@v1 requires API routePrefix - AsgiFunction App

if routePrefix is empty in the host.json, then the GitHub action [static-web-apps-deploy@v1](https://github.com/Azure/static-web-apps-deploy/tree/v1) will throw:

Error in processing api build artifacts: the host.json file cannot specify a http.routePrefix value other than 'api'.

**Surely this can just be made into a warning...**

I would like to use AsgiFunction app (with FastAPI) but FastAPI prepends its routes with a **/** and AsgiFunction postpends its api route with **/** so host.json routePrefix needs to be left empty **""** for most ASGI apps otherwise you'll get consecutive **//** routing error.

If this can be made into a warning one can add the API prefix in their Asgi app instead (in fastAPI router).