lines 39 - 46 become:
      foreach( $notes as $note ) {
        if( $note->customer_note ) {
        } else {
          print '<li class="order_private_note">';
          $date = date( 'd/m/y H:i', strtotime( $note->date_created ) );
          print $date.' by '.$note->added_by.'<br>'.$note->content.'</li>';
        }
      }