document.addEventListener("DOMContentLoaded", function (event) {
    setTimeout(function() {
        document.querySelectorAll('*').forEach.call(
            document.querySelectorAll('img[data-src]'),
            function (img) {
                img.setAttribute('src', img.getAttribute('data-src'));
                img.onload = function () {
                    img.removeAttribute('data-src');
                };
            });
    },200);
});