Do not add the `/api/v1` if not reneeded

[edouardbruelhart]

Here I propose to ignore paths that start with "/api" or that are equal to "/" to remove unnecessary parts, but to keep other ones to avoid 404 errors.

[suricactus]

This PR fixes https://github.com/opengisch/qfieldsync/issues/605#issuecomment-2298187889