Modify a theme

Just hide using css:

article#no-results {
    display: none;
}

If you’re not using a Child Theme, and if the theme doesn’t have a designated section of the dashboard for CSS modifications then do the following:

1. Install this Custom CSS Manager plugin http://wordpress.org/plugins/custom-css-manager-plugin
2. use its “CSS Code” section of the dashboard to hold your CSS modifications:
3. (put this code in)

   article#no-results {
       display: none;
   }

4. Save

Alternatively use your Child Theme style.css file to hold your CSS modifications