Set tabindex on button <div> instead of <a>
Set tabindex on button <div> instead of <a>

This apparently makes Firefox happy

See also I6cf69c7e

Bug: 65554
Change-Id: I1a11f43a6e2e9f1cbbe243a599caa507c705e13c

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui