Setting WebClient.Proxy to null stops the local api from working

[haefele]

In an environment where I have setup a proxy in my internet settings the local spotify api is not working.

It seems that the issue is in these two lines, where the WebClient.Proxy property is set specifically to null.

https://github.com/JohnnyCrazy/SpotifyAPI-NET/blob/master/SpotifyAPI/Local/RemoteHandler.cs#L65
https://github.com/JohnnyCrazy/SpotifyAPI-NET/blob/master/SpotifyAPI/Local/ExtendedWebClient.cs#L13

I am unsure why they are specifically set to null, but maybe you guys can tell me that.

I also would be happy to make a pull request to fix this by myself, but first I would like to discuss how this should be fixed (just to match your architectural expectations).

[JohnnyCrazy]

@haefele I had problems with not setting it to null, but that was before I released the library and was propably related to some misconfiguration on my system.

Feel free to create a PR 👍

[JohnnyCrazy]

Fixed by #58