simply privileged port logic for local sockets on TrueNAS HA

Trying to troubleshoot and track down the memory leak here: https://jira.ixsystems.com/browse/NAS-104437 has shown that we can dramatically simply the middlewared Client() code.

Essentially, we do not need to import ctypes and use direct C API calls to reserve a privileged port. We can simply call `sock.bind(('', port)).