OF-1292 fix NPE when canceling new room creation on admin console

src/web/muc-room-edit-form.jsp

@@ -87,7 +87,13 @@
 
     // Handle a cancel
     if (request.getParameter("cancel") != null) {
+        if (roomJID == null) {
+            // case when canceling creating a new room
+            response.sendRedirect("muc-room-summary.jsp");
+        } else {
+            // case when canceling a room edit, used on summary to set service
             response.sendRedirect("muc-room-summary.jsp?roomJID="+URLEncoder.encode(roomJID.toBareJID(), "UTF-8"));
+        }
         return;
     }