Update documentation for dynamic buffer resizing.

examples/mqtt_auth/mqtt_auth.ino

@@ -27,9 +27,9 @@ void setup()
 {
   Ethernet.begin(mac, ip);
   // Note - the default maximum packet size is 128 bytes. If the
-  // combined length of clientId, username and password exceed this,
-  // you will need to increase the value of MQTT_MAX_PACKET_SIZE in
-  // PubSubClient.h
+  // combined length of clientId, username and password exceed this use the
+  // following to increase the buffer size:
+  // client.setBufferSize(255);
   
   if (client.connect("arduinoClient", "testuser", "testpass")) {
     client.publish("outTopic","hello world");