Disable localhost from being tracked

Hi, thanks for sharing your work!

I was trying to disable GA from tracking localhost with no luck, here is my code

```
onMount(async () => {
	if ($page.host.split(':')[0] == 'localhost') { 
	console.log(window)
		window['ga-disable-G-XXXXXXXXX'] = true; // enter your tracking ID
		console.log('disabled GA for localhost!')
	}
});

let ga_measurment_id = "G-XXXXXXXXX"
```