Hi all,

I'm seeing some unexpected behavior from $http_rs when using http_async_query() to send a POST request to an endpoint that requires Basic (username/password) authentication.

When I use:

```
$http_req(username) = "someuser";
$http_req(password) = "somepass";
```

the request goes through and the server responds with a 201 Created, as expected. The response body ($http_rb) contains the correct result. However, $http_rs still shows 401 Unauthorized.

I believe this happens because curl receives a 401 challenge first, then retries with the provided credentials and gets the correct 201. It seems $http_rs is reflecting the status from the initial challenge rather than the final response. This is on Kamailio v6.0.1.

As a workaround, I tried manually setting the Authorization header like this:

```
$var(credentials) = "someuser:somepass";
$http_req(hdr) = "Authorization: Basic " + $(var(credentials){s.encode.base64});
```

In that case, $http_rs correctly shows 201.

Is it expected for $http_rs to stay at 401 in the first scenario? Or should it reflect the final status code after curl completes the full request cycle?

Thanks,
Joel.