iOS Issues

1. Webview launches with "Success" but only with a white empty page which then launches Safari.

2. After closing the webview, you cannot open it again.

```
webview.Show(
    url,
    function onSuccess(){
      console.log('Success');
      app.hideLoading();
    },
    function onError(error){
      console.log('Error opening presentation.');
    }
);
```