fix closing of closed ws.Authed channel when client AUTHs twice.

utils.go

@@ -14,6 +14,9 @@ const (
 
 func RequestAuth(ctx context.Context) {
 	ws := GetConnection(ctx)
+	ws.authLock.Lock()
+	ws.Authed = make(chan struct{})
+	ws.authLock.Unlock()
 	ws.WriteJSON(nostr.AuthEnvelope{Challenge: &ws.Challenge})
 }