bind: security bump to version 9.9.6-P2

Fixes CVE-2015-1349 - Revoking a managed trust anchor and supplying an
untrusted replacement could cause namedto crash with an assertion
failure.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>