2708. [func] Insecure to secure and NSEC3 parameter changes via
update are now fully supported and no longer require defines to enable. We now no longer overload the NSEC3PARAM flag field, nor the NSEC OPT bit at the apex. Secure to insecure changes are controlled by by the named.conf option 'secure-to-insecure'. Warning: If you had previously enabled support by adding defines at compile time to BIND 9.6 you should ensure that all changes that are in progress have completed prior to upgrading to BIND 9.7. BIND 9.7 is not backwards compatible.