make bigcouch admin process listen only on 127.0.0.1

we just need to update /opt/bigcouch/etc/vm.args for that to include:

-kernel inet_dist_listen_min 9002 inet_dist_use_interface "{127,0,0,1}"

see https://leap.se/code/issues/2685#note-8

(from redmine: created on 2013-12-29, closed on 2014-01-04)