lnd: update invoiceRegistry to match new switch requirements

rpcserver.go

@@ -2799,7 +2799,7 @@ func (r *rpcServer) LookupInvoice(ctx context.Context,
 
 	rpcsLog.Tracef("[lookupinvoice] searching for invoice %x", payHash[:])
 
-	invoice, err := r.server.invoices.LookupInvoice(payHash)
+	invoice, _, err := r.server.invoices.LookupInvoice(payHash)
 	if err != nil {
 		return nil, err
 	}