Fix BIND performance.
Fix BIND performance.

BIND was using 100% of the CPU on the master VM.  This turns out to be
related to Red Hat BZ #709205.  This change fixes BIND's performance.

The URL for the BZ is: https://bugzilla.redhat.com/show_bug.cgi?id=709205

caess/sysadmin-cucumber-demo,caess/sysadmin-cucumber-demo