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/api/atom_api_session.cc
const scoped_refptr<net::URLRequestContextGetter>& context_getter,
    Session::CacheAction action,
    const net::CompletionCallback& callback) {
  auto request_context = context_getter->GetURLRequestContext();
  auto http_cache = request_context->http_transaction_factory()->GetCache();
  if (!http_cache)
    RunCallbackInUI<int>(callback, net::ERR_FAILED);
  
  using BackendPtr = disk_cache::Backend*;
  auto* backend_ptr = new BackendPtr(nullptr);
  net::CompletionCallback on_get_backend =
      base::Bind(&OnGetBackend, base::Owned(backend_ptr), action, callback);
  int rv = http_cache->GetBackend(backend_ptr, on_get_backend);
  if (rv != net::ERR_IO_PENDING)
    on_get_backend.Run(net::OK);
}
void SetProxyInIO(net::URLRequestContextGetter* getter,