fixed dashboard notice

fixed dashboard notice (on fresh install 2.3 beta, $theme_options is empty object)

Also, the system/cms/src/Pyro/Model/EloquentCollection.php has this method:
```php
    public function save()
    {
        $this->each(
            function ($model) {
                $model->delete();
            }
        );
    }
```
changed delete to 'save()', probably it's a valid fix?

Thanks