adapt to recent API changes

index.html

@@ -12,7 +12,7 @@
 
     function sendMsg() {
         msg = document.getElementById("input").value;
-        window.webxdc.sendUpdate('someone typed "'+msg+'"', {"name": window.webxdc.selfName(), "msg": msg});
+        window.webxdc.sendUpdate({"name": window.webxdc.selfName(), "msg": msg}, 'someone typed "'+msg+'"');
     }
 
     function receiveUpdate(update) {

webxdc.js

@@ -25,7 +25,7 @@ window.webxdc = (() => {
             var updatesJSON = window.localStorage.getItem(updatesKey);
             return updatesJSON ? JSON.parse(updatesJSON) : [];
         },
-        sendUpdate: (description, payload) => {
+        sendUpdate: (payload, description) => {
             // alert(description+"\n\n"+JSON.stringify(payload));
             var update = {payload: payload};
             updateListener(update);