Scroll=False breaks z-indexing for modals

[mhartington]

if you have an ion-content, set the scroll to false and then open the modal, it breaks some z-index.

http://codepen.io/mhartington/pen/EjjmGK

If you comment out this style or change the value to 10, it fixes the issue, but not sure what it breaks.

.scroll-content-false, .menu .scroll-content.scroll-content-false {
  z-index: 11;
}