Fix the protocol of the gqtp package and change default port number in client mode.

I have found mistakes the protocol of the groonga-server-gqtp package.
So I fixed it.

I propose change default port number in client mode.
Because, gqtp default port number is 10043.

And I fixed the document.
But... I failure "make html". Sphinx is too difficult :<

https://github.com/naoa/groonga/commit/7887eb40738b2ea82d9268814bdaf96b586e8145

The following is the error message.

```
Error: The six module cannot be found. Did you install Sphinx and its dependencies correctly?
```