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_url_request.cc
const std::string& value) {
  
  if (!request_state_.NotStarted()) {
    
    return false;
  }
  if (!net::HttpUtil::IsValidHeaderName(name)) {
    return false;
  }
  if (!net::HttpUtil::IsValidHeaderValue(value)) {
    return false;
  }
  DCHECK(atom_request_);
  if (atom_request_) {
    atom_request_->SetExtraHeader(name, value);
  }
  return true;
}
void URLRequest::RemoveExtraHeader(const std::string& name) {