Open modal is shifting fixed navbar to the right

Created by: mhawk0

re: https://github.com/twbs/bootstrap/issues/9855 in 3.2.0, when body has a scrollbar, it's content now stays in place when modal is opened (padding is added to the body). But fixed top navbar, having position: fixed, left: 0 and right: 0, now jumps to the right when modal is opened, as it ignores padding-right on the body.