title: how to set only vertical for perfect scroll in rtl direction
body: <p>I used <a href="https://github.com/noraesae/perfect-scrollbar" rel="nofollow noreferrer">perfect-scroll</a> but this plugin put Y and X scroll bars. How to disable x scroll?</p>
  
  <p>I found this <a href="http://www.f1s.me/jscroll/examples/options-useBothWheelAxes.html" rel="nofollow noreferrer">page</a> but haven't codes ..</p>
  
  <pre><code>$(document).ready(function ($) {
      $('.sidebar').perfectScrollbar({
          useBothWheelAxes: false
      })
  });
  </code></pre>