fix disconnect screen taking precedence over error screen

closes #68

static/index.js

@@ -98,6 +98,10 @@ function readUrl(urlString) {
         },
 
         async onDisconnect() {
+            if (session.errored) return; // Display the error screen
+
+            console.info("showing disconnected refresh screen");
+
             let duration = 5000 + Math.random() * 1000;
             while (true) {
                 console.info("waiting a bit for the server to come back up", duration);