Window: Fixed loss of focus when navigating with shift + tab key
Window: Fixed loss of focus when navigating with shift + tab key

Sets tabindex property to -1, if set to 0 makes it seem like
focus is lost when user navigates the dialog using shift + tab key.

Bug: T257385
Change-Id: I0f278d840ebc3fb85be937b442486343fe489d48

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