Fix 'undefined method `windows?` for Puma:Module' when execute pumactl.
Fix 'undefined method `windows?` for Puma:Module' when execute pumactl.

```
$ bundle exec pumactl --pid tmp/pids/puma.pid stop
=> undefined method `windows?' for Puma:Module
```

kyledrake/puma,prathamesh-sonpatki/puma,puma/puma,eileencodes/puma,kyledrake/puma,eileencodes/puma,looker/puma,respire/puma,looker/puma,kyledrake/puma,ngpestelos/puma,eileencodes/puma,eileencodes/puma,unleashed/puma,puma/puma,ngpestelos/puma,respire/puma,prathamesh-sonpatki/puma,puma/puma,prathamesh-sonpatki/puma,kyledrake/puma,prathamesh-sonpatki/puma,looker/puma,puma/puma,unleashed/puma,ngpestelos/puma,unleashed/puma,ngpestelos/puma,unleashed/puma,respire/puma,looker/puma,respire/puma