Will be nice to clear auth credentials. For example, I'm using a proxy that accepts options via username:

```
proxy.com:8080
user: wiliam_country_US
```

So, if I want to change the peer node, I change my username:

```
proxy.com:8080
user: wiliam_country_GB
```

But, I'm not changing the proxy, so electron has valid credentials and is not going to trigger `login` event.

I'm searching the way to clean auth settings so electron asks them again.
atom/browser/net/atom_url_request.cc
scoped_refptr<net::HttpResponseHeaders> response_headers) const {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  if (delegate_)
    delegate_->OnResponseStarted(response_headers);
}
void AtomURLRequest::InformDelegateResponseData(
    scoped_refptr<net::IOBufferWithSize> data) const {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  
  
  if (delegate_)
    delegate_->OnResponseData(data);
}
void AtomURLRequest::InformDelegateResponseCompleted() const {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  if (delegate_)
    delegate_->OnResponseCompleted();
}
void AtomURLRequest::InformDelegateErrorOccured(const std::string& error,
                                                bool isRequestError) const {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  if (delegate_)
    delegate_->OnError(error, isRequestError);
}
}