fixed an issue with master installation not creating reverse zone
    
    When resolv.conf is set to point to the master's ip before installation, the
    ipa-server-install does not create a reverse zone for it's ip even despite
    --auto-reverse option provided. The fix is not to mess around with resolv.conf
    before master installation.
    
    Reviewed-By: Petr Spacek <pspacek@redhat.com>