Update options.rb to allow `proxy` to be `nil`. (#812)
Update options.rb to allow `proxy` to be `nil`. (#812)

Allow `proxy` to be `nil` so the client can be instantiated like this:

```ruby
Savon.client(
    wsdl: 'some.wsdl',
    ...

    proxy: ENV['savon_proxy'].present? ? ENV['savon_proxy'] : nil
  )
```
savonrb/savon