reject promise on WebSocket initiation failure.

relay.ts

@@ -85,7 +85,11 @@ export function relayInit(
 
   async function connectRelay(): Promise<void> {
     return new Promise((resolve, reject) => {
-      ws = new WebSocket(url)
+      try {
+        ws = new WebSocket(url)
+      } catch (err) {
+        reject(err)
+      }
 
       ws.onopen = () => {
         listeners.connect.forEach(cb => cb())