Update bind97 package to 9.7.4.

Update bind97 package to 9.7.4.

For full changes, please refer:
ftp://ftp.isc.org/isc/bind9/9.7.4/RELEASE-NOTES-BIND-9.7.4.html

New Features

9.7.4

     * A new test has been added to check the apex NSEC3 records after
       DNSKEY records have been added via dynamic update. [RT #23229]
     * Added a tool able to generate malformed packets to allow testing of
       how named handles them. [RT #24096]

Security Fixes

9.7.4

     * named, set up to be a caching resolver, is vulnerable to a user
       querying a domain with very large resource record sets (RRSets)
       when trying to negatively cache the response. Due to an off-by-one
       error, caching the response could cause named to crash. [RT #24650]
       [CVE-2011-1910]
     * Change #2912 (see CHANGES) exposed a latent bug in the DNS message
       processing code that could allow certain UPDATE requests to crash
       named. [RT #24777] [CVE-2011-2464]

Feature Changes

9.7.4

     * Merged in the NetBSD ATF test framework (currently version 0.12)
       for development of future unit tests. Use configure --with-atf to
       build ATF internally or configure --with-atf=prefix to use an
       external copy. [RT #23209]
     * Added more verbose error reporting from DLZ LDAP. [RT #23402]
     * Replaced compile time constant with STDTIME_ON_32BITS. [RT #23587]