cli: set TCP_NODELAY for HTTP request socket

lua is using multiple send() calls per request. All data but the one
coming from the first send() will be delayed, increasing request
latency. TCP_NODELAY fixes latency at the cost of sending more
packets.

The best would be to fix lua's http library.

Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>