QWebEngineUrlRequestInterceptor ignores extra HTTP headers when redirecting

QWebEngineUrlRequestInterceptor::interceptRequests allows intercepting requests made by the web site and inspect or modify them. Among others it allows:

• setting custom HTTP headers via QWebEngineUrlRequestInfo::setHttpHeader
• redirecting the browser to a custom URL via QWebEngineUrlRequestInfo::redirect

While both of the features work fine alone, the don't work combined, which means that when redirecting a browser request and adding custom headers, the redirection works, but the custom headers are not added to the new redirected request.