Fix simple-balancer example

The balancer example will only work for the first two requests, as the `target` that is pushed back to `addresses` has the form:

```js
{
    target: {
        host: 'ws1.0.0.0',
        port: 80
    }
}
```

when should be like this:

```js
{
    host: 'ws1.0.0.0',
    port: 80
}
```