Fixes a bug where passed to route() causes errors
Fixes a bug where passed to route() causes errors

This attempts to fix #510 even though the example provided by @zsoltgyure isn't actually using route model binding.

This bugfix was tested and works with the following.

Non-route model binding:
```
{{ Form::open(['route' => ['mytest', [$file->id]]]) }}
```

Another non-route model binding:
```
{{ Form::open(['route' => ['mytest', $file->id]]) }}
```

Multiple models into route model binding:
```
{{ Form::open(['route' => ['manage.files.delete', [$currentPodcast, $file]]]) }}
```

Single model into route model binding:
```
{{ Form::open(['route' => ['manage.podcast.delete', $currentPodcast]]) }}
```

laravie/html,LaravelCollective/html