Remove world-readable/traversable bits from permissions on the BIND
DNSSEC keys directory and the keys themselves (not actually
necessary for the public key files, but added for consistency as
they share a directory with the private keys). Note that this
matches the permissions and ownership of the existing
adns1.openstack.org server.
Change-Id: I015777ee346fefcaa92e64ad2ee88a41c7ea9bde