monitor2: fix status interface js error according to dom

Fixing almost random error: cannot get `parentNode` of null

stack/monitor2/buildout.cfg

@@ -80,7 +80,7 @@ md5sum = a18ab932e5e2e656995f47c7d4a7853a
 [monitor-web-monitor-js]
 <= monitor-download-base
 filename = monitor.js.in
-md5sum = 8bc4b8368a752f90da2571866768e81f
+md5sum = 65799bea0e09147ef9cbcbb46fcb1c1d
 
 [monitor-web-monitor-logout-cgi]
 recipe = slapos.recipe.template:jinja2

stack/monitor2/monitor.js.in

@@ -152,8 +152,11 @@
       "<p>Red square means the feature has a problem, green square means it is ok.</p>",
       "<p>You can click on a feature below to get more precise information.</p>"
     ].join("\n")), div = document.createElement("div"), tmp;
-    [].forEach.call(element_list, function (element) {
-      if (element.parentNode.parentNode) { return; }
+    [].reduce.call(element_list, function (array, element) {
+      if (element.parentNode.parentNode) { return array; }
+      array.push(element);
+      return array;
+    }, []).forEach(function (element) {
       root.appendChild(element);
     });
     document.title = monitor_title;