title: How to avoid showing loading text in Ext.form.ComboBox?
body: <p>I use Ext.form.ComboBox in very similar way as in this example:
  <a href="http://extjs.com/deploy/dev/examples/form/forum-search.html" rel="nofollow noreferrer">http://extjs.com/deploy/dev/examples/form/forum-search.html</a></p>
  
  <p>What annoys me is that when the ajax call is in progress it shows loading text and I cannot see any results from before. </p>
  
  <p>Eg I input 'test' -> it shows result -> I add 'e' (search string is 'teste') -> result dissapear and loading text is shown, so for a second I cannot see any result and think about if it's not what I'm searching for...</p>
  
  <p>How can I change this to simply not to say anything when 'loading'...</p>