SonarQube is missing the mandatory `WWW-Authenticate` header in 401 responses

With using Community Edition Version 9.9 (build 65466), I tried to use the web_api with the java.net http client.

Now I have the problem that it first makes an unauthenticated call and gets a 401 response.

But this response is missing the WWW-Authenticate header that is mandatory for such responses and aborts with an error instead of trying again with basic authentication.

SonarQube should properly set the WWW-Authenticate header in 401 responses.

Work-around is to user preemptive authentication by constructing and setting the authorization header explicitly instead of using an Authenticator.