If you want to enable the horizontal scrollbar to body instead of a certain div, you have to delete the code below from your adminlte.js
And set all divs before to width:100%;
Layout.prototype.fix = function () {
// Remove overflow from .wrapper if layout-boxed exists
$(Selector.layoutBoxed + ' > ' + Selector.wrapper).css('overflow', 'hidden');
// Get window height and the wrapper height
var footerHeight = $(Selector.mainFooter).outerHeight() || 0;
var neg = $(Selector.mainHeader).outerHeight() + footerHeight;
var windowHeight = $(window).height();
var sidebarHeight = $(Selector.sidebar).height() || 0;
// Set the min-height of the content and sidebar based on
// the height of the document.
if ($('body').hasClass(ClassName.fixed)) {
$(Selector.contentWrapper).css('min-height', windowHeight - footerHeight);
} else {
var postSetHeight;
if (windowHeight >= sidebarHeight) {
$(Selector.contentWrapper).css('min-height', windowHeight - neg);
postSetHeight = windowHeight - neg;
} else {
$(Selector.contentWrapper).css('min-height', sidebarHeight);
postSetHeight = sidebarHeight;
}
// Fix for the control sidebar height
var $controlSidebar = $(Selector.controlSidebar);
if (typeof $controlSidebar !== 'undefined') {
if ($controlSidebar.height() > postSetHeight)
$(Selector.contentWrapper).css('min-height', $controlSidebar.height());
}
}
};