Support no redirect in frontend selector

See merge request !1

selector.html

@@ -1167,7 +1167,13 @@ window.RSVP = requireModule("rsvp");
         } else {
           msg += "<tr>";
         }
-        msg += '<td><a href="' + table_dict[u].url + '">' + u + '</a></td>';
+        msg += "<td>";
+        if (table_dict[u].url) {
+          msg += '<a href="' + table_dict[u].url + '">' + u + '</a>';
+        } else {
+          msg += u;
+        }
+        msg += "</td>";
         for (y in interaction_dict) {
           if (interaction_dict.hasOwnProperty(y)) {
             msg += "<td>" + table_dict[u][y] + "</td>";