MB-100: fix iptables Bad state in xdcr

[root@localhost ~]# /sbin/iptables -A INPUT -m state --state ESTABLISHED, RELATED -j ACCEPT
iptables v1.3.5: Bad state `'
Try `iptables -h' or 'iptables --help' for more information.
[root@localhost ~]# /sbin/iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
[root@localhost ~]#

Change-Id: I1b2792df303fb5b6e5ec129801be7d9acc7977b3
Reviewed-on: http://review.couchbase.org/24916
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>