SelectWidget: Really prevent default action during type-to-select
SelectWidget: Really prevent default action during type-to-select

Contrary to the documentation, this was a plain DOM event handler (and
not jQuery event handler), so returning 'false' didn't do anything.

Bug: T126239
Change-Id: Icf48579e53f8e17178a7b5dbe5e6ab5ee7ef0c0f

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