Fix snippet: fetch.js - json file can't be fetched

### URL no longer returns a json file,

- maybe change fetch to a valid JSON file.

- https://freegeoip.net/json/ now returns:
```
"4": "# This API endpoint is deprecated and has now been shut down.
```

* Ref:
- https://github.com/eclipsesource/tabris-js/blob/master/snippets/fetch.js

```js
function loadData() {
fetch('https://freegeoip.net/json/')
```
Thanks,
Rob