Simply edit the file C:\Program Files\DeskNow\desknow\jsp\original\Login_default.jsp ( /var/desknow/desknow/jsp/original/Login_default.jsp) and add the following lines at the very beginning of the file:

<%
 if(request.getRequestURL().substring(0,5).equals("http:")) {
  response.sendRedirect("https://www.server.com/desknow/index.html");
 }
%>