Remove scroll animation for z* command due to flickering

The current setting makes z* command flickering when navigating via z* command. It could be caused by vim renders the target view at fist then rollback to start view and redraw animations to target view, then showing the target view at first causes flickering.  But we still need update the last saved view after z* command even if we don't do scrolling, or the following scroll will be very weird.