QSslConfiguration::setDefaultConfiguration() does not set new ssl configuration for future QNetworkRequest s

1. QNetworkAccessManager d
2.  /* set default configuration without certificates at all */
     QSslConfiguration::setDefaultConfiguration(QSslConfiguration::defaultConfiguration().setCaCertificates(QList<QSslCertificate>))
3. d.get(QNetworkRequest("https://evil.com"))
4.  ( as, the CaCerts are emty, we will go to QNetworkAccessManager::sslErrors signal connected with our slot  in which we will add certificate)
5. in slot:  
   QSslConfiguration sc= QSslConfiguration::defaultConfiguration();
   sc.setCaCertificates(QList<QSslCertificate>() << reply->sslConfiguration()->peerCertificateChain().last() ) ;
   QSslConfiguration::setDefaultConfiguration(sc);
   /* slot complete */
6. QNetworkRequest * xxx=QNetworkRequest("https://evil2.com");
7. xxx->sslConfiguration().caCertificates().size()  will be 0 !!! but should not !!!