update readme

README.md

@@ -193,11 +193,12 @@ using msghandler, NATS
 conn = NATS.connect("nats.yiem.cc")
 NATS.subscribe(conn, "test.topic") do msg
   println("Received message on $(msg.subject)")
+  payloads = String(msg.payload)
   
   # Use NATSBridge.smartreceive to handle the data
   # API: smartreceive(msg, download_handler; max_retries, base_delay, max_delay)
   envelope = msghandler.smartunpack(
-    msg;
+    payloads;
     max_retries = 5,
     base_delay = 100,
     max_delay = 5000