screen.waitFor() does not return when setting non-default timeout

**Version**

1.5.0

**Description**

The following minimal example will throw an exception, but the progam will not return. If you set the default value of 5000, it works as expected.

```
const nut = require('@nut-tree/nut-js')
async function run() {
	await nut.screen.waitFor('test.png', 10000) // 5000 would work
}
run()
```

**Issue occurs on**
- [x] Dev/Host system (GNU/Linux)