don't crash js if a backend service is not running

airtime_mvc/public/js/airtime/status/status.js

@@ -46,6 +46,7 @@ function success(data, textStatus, jqXHR){
 
     for (var key in services) {
         var s = services[key];
+        if (s) {
             var children = $("#"+s.name).children();
             $(children[0]).text(s.name);
             
@@ -61,6 +62,7 @@ function success(data, textStatus, jqXHR){
             $(children[3]).text(s.cpu_perc);
             $(children[4]).text(sprintf('%01.1fMB (%s)', parseInt(s.memory_kb)/1000, s.memory_perc));
         }
+    }
     if (data.status.partitions){
         generatePartitions(data.status.partitions);
     }