CC-4943: Raspberry Pi optimization: don't create new background AJAX request until the previous one has returned

-fixed

airtime_mvc/public/js/airtime/showbuilder/main_builder.js

@@ -277,12 +277,13 @@ AIRTIME = (function(AIRTIME) {
                     if (json.update === true) {
                         oTable.fnDraw();
                     }
+                    setTimeout(checkScheduleUpdates, 5000);
                 }
             });
         }
 
         //check if the timeline view needs updating.
-        setInterval(checkScheduleUpdates, 5 * 1000); //need refresh in milliseconds
+        checkScheduleUpdates();
     };
 
     mod.onResize = function() {