Only show heartbeat toast once HTTP request is complete

Server/public/res/js/node.js

@@ -86,7 +86,7 @@ function sendNodeHeartbeat(nodeId){
     Http.open("GET", url);
     Http.send();
 
-    Http.onreadystatechange = (e) => {
+    Http.onloadend = (e) => {
     console.log(Http.responseText)
     createToast(Http.responseText);
     }