Fixed package remove action

When trying to remove a chocolatey package, I am getting a ```undefined method `package' for nil:NilClass``` exception.

**Stacktrace**
```
c:/chef/cache/cookbooks/chocolatey/providers/default.rb:62:in `block (3 levels) in class_from_file'
c:/chef/cache/cookbooks/chocolatey/providers/default.rb:61:in `block (2 levels) in class_from_file'
c:/chef/cache/cookbooks/chocolatey/providers/default.rb:60:in `block in class_from_file'
```

Somehow, this code change fixes it, _and I don't even know why_