title: Pagination with query string gives error page not found
body: <p>My controller is this:</p>
  
  <pre><code>$config['base_url'] = base_url().'category';
  $config['uri_segment'] = 3;
  $config['reuse_query_string'] = TRUE;
  $config['enable_query_strings']=TRUE;
  $config['use_page_numbers'] = TRUE;
  $config['total_rows'] = $allcount;
  $config['per_page'] = $rowperpage;
  </code></pre>
  
  <p>When I click on 2nd page it shows an error <strong>page not found</strong> </p>