nutcracker: correct whitespace in config, stats port

nutcracker was not starting along with the older twemproxy because
of a whitespace in the config file, and of sharing the same default
 monitoring port with the old instance.

Change-Id: I63b2a0d5b94db32a6c606f186a387beb824e0f44
Signed-off-by: Giuseppe Lavagetto <glavagetto@wikimedia.org>