stop moxi from refusing to run under root

Because nobody cares. And because our memcached fork has been updated
to don't care as well.

Change-Id: I5627c37e26f827a74a62aad115a8940e3fa2815a
Reviewed-on: http://review.couchbase.org/35506
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>