Luna Menu Fix

## Old:

  def index=(index)
    draw_item(@index) if @index >= 0
    @index = index
    draw_item(@index) if @index >= 0
    update_cursor
    call_update_help
  end


## New:

  def index=(index)
    last_index = @index
    @index = index
    draw_item(last_index) if last_index >= 0
    draw_item(@index) if @index >= 0
    update_cursor
    call_update_help
  end