title: jqgrid multiselect filter issue with grid refresh
body: <p>I was checking the <a href="http://www.ok-soft-gmbh.com/jqGrid/simplelocalgridwithsearchingtoolbarmultilpe1.htm" rel="nofollow noreferrer">demo</a> to implement Multiselect filtering in my project.</p>
  
  <p>It is a nice demo indeed but has some issues with it.
  Select a filter and hit the refresh button then filters are not resetting. And after that it will starts malfunctioning.</p>
  
  <h2>Select a filter:</h2>
  
  <p><img src="https://i.stack.imgur.com/ff21p.png" alt="Select a filter"></p>
  
  <h2>After hitting refresh:</h2>
  
  <p>Filters are not resetting
  <img src="https://i.stack.imgur.com/ZnTXb.png" alt="After hitting refresh"></p>
  
  <h2>Now unchecked the filter:</h2>
  
  <p><img src="https://i.stack.imgur.com/DQ4WK.png" alt="enter image description here">
  Got empty grid.
  <img src="https://i.stack.imgur.com/jrtvV.png" alt="Now unchecked the filter"></p>
  
  <p>How can I fix these issues? Any Idea. </p>