graphs: disable animation during live update

dashboard/src/components/CpuUsage.vue

@@ -48,7 +48,7 @@ async function liveRefresh() {
     if (!data.cpu[0]) return; // value can be null if no previous value
     gGraph.data.labels.push(moment(data.cpu[1]*1000).format('hh:mm'));
     gGraph.data.datasets[0].data.push(data.cpu[0]);
-    gGraph.update();
+    gGraph.update('none'); // disables animation
   };
 }