Don’t show hero image on IE8
Don’t show hero image on IE8

IE8 doesn’t support background-size, so the image appears too big, the
text overlaps it, and everything becomes a mess.

alphagov/notifications-admin,alphagov/notifications-admin,alphagov/notifications-admin,gov-cjwaszczuk/notifications-admin,gov-cjwaszczuk/notifications-admin,gov-cjwaszczuk/notifications-admin,alphagov/notifications-admin,gov-cjwaszczuk/notifications-admin