Typo in node tutorial leads to wrong transport being used

In the node tutorial (tutorial/nodejs/NodeClient.js), lines like `transport = thrift.TBufferedTransport()` cause transport to be undefined, which later get replaced with the default, so this example does work.

I found the issue when using `thrift.TFramedTransport()`, which was erroring on the server side. It took me a while to figure out that the transport was falling back to buffered, because I was actually assigning the transport to undefined.

Changing the lines to assign thrift.TFramedTransport instead of thrift.TFramedTransport() fixed it for me.