Magnific popup iframe closeOnBgClick does not work

Question

There is some case when a popup shouldn't be closed by clicking the background. After googling here and there still no success on that. This is the code:

jQuery('.magnific_link').magnificPopup({
    type: "iframe",
    fixedContentPos: true,
    closeOnBgClick: false,
    iframe: {
        markup: '<div class="mfp-iframe-scaler">'+
        '<div class="mfp-close"></div>'+
        '<iframe class="mfp-iframe" style="background:white;" frameborder="0" allowfullscreen></iframe>'+
        '</div>',
        patterns: {
            test: {
                index: '',
                id: function (url) {
                    var m = url.match(/^(.*)/);
                    return m === undefined ? null : m[1];
                },
                src: "%id%"
            }
        }
    }
});

Any idea what is going wrong? Thanks