Remove > 65535 validation from --server.port

Remove > 65535 validation from --server.port

While trying to implement the upcoming patch, I found myself trying to
refactor this validation. The implementation was awkward; instead of
ntohs'ing sockaddr_in.sin_port, it extracted the bytes manually:

	port = (unsigned char)((*result)->ai_addr->sa_data[0]) << 8;
	port += (unsigned char)((*result)->ai_addr->sa_data[1]);

But on second thought, I'm not seeing this validation eye to eye.
It's intended to prevent `getaddrinfo()` from parsing
`--server.port=120000` like `--server.port=54464` (120000 % 65536) on
Linux, but... thing is, this "port out of bounds" quirk looks like an
everyday Linux idiosyncrasy.

Linux being Linux:

	$ nc -lv 127.0.0.1 120000
	Listening on localhost 54464

It's weird but seems inoffensive, and some beardos might even expect it.

`getaddrinfo()` returns proper errors in the BSDs, so the validation is
redundant there.