Update Example3_InboundPolling.ino (#41)

It should be inbound mode for periodic communication.

Author: spamv

examples/Example3_InboundPolling/Example3_InboundPolling.ino

@@ -72,7 +72,7 @@ void setup()
     JAddBoolToObject(req, "sync", true);  // Automatically sync when changes are made on notehub
 #else
     JAddStringToObject(req, "mode", "periodic");
-    JAddNumberToObject(req, "outbound", 60);
+    JAddNumberToObject(req, "inbound", 60);
 #endif
     notecard.sendRequest(req);