Added "signal" key in fetch init object makes iOS fail (react-native)

[mrclay]

The key is set to undefined but even the presence of the key blocks iOS from sending the request.

Workaround for this:

const api = new Api({
  customFetch: (url, init) => {
    const clonedInit = {...init};
    delete clonedInit.signal;
    return fetch(url, clonedInit);
  },
});