have you tried this? look \here

$user = 'admin';
$password = 'mY5up3rPwd';
$dbname = 'test';

$server_url = 'https://www.monsite.com:8069'; //connexion sécurisée
$connexion = \new xmlrpc_client($server_url . "/xmlrpc/common");
$connexion->setSSLVerifyPeer(0);

$c_msg = \new xmlrpcmsg('login');
$c_msg->addParam(\new xmlrpcval($dbname, "string"));
$c_msg->addParam(\new xmlrpcval($user, "string"));
$c_msg->addParam(\new xmlrpcval($password, "string"));
$c_response = $connexion->send($c_msg);