Fix unbound on rax centos6 nodes.

Rax centos6 nodes are dynamically configured via static file injection.
During boot our rc.local script runs to set resolv.conf nameserver to
127.0.0.1 then the ifup-post script runs and overwrites this
information with the "static" info in the ifcfg-* files. Modify the
ifcfg-* files in rc.local to prevent them from updating the nameservers
in resolv.conf.

Change-Id: I532e9fa4c40e0e0ce2aad35f4ae1f385a0619b70
Merge "Fix unbound on rax centos6 nodes."