bind: Update to 9.11.18

bind: Update to 9.11.18

For details see:
https://downloads.isc.org/isc/bind9/9.11.18/RELEASE-NOTES-bind-9.11.18.html

"Security Fixes

DNS rebinding protection was ineffective when BIND 9 is configured as a forwarding
DNS server. Found and responsibly reported by Tobias Klein. [GL #1574]

Known Issues

We have received reports that in some circumstances, receipt of an IXFR can cause
the processing of queries to slow significantly. Some of these were related to RPZ
processing, which has been fixed in this release (see below). Others appear to occur
where there are NSEC3-related changes (such as an operator changing the NSEC3 salt
used in the hash calculation). These are being investigated. [GL #1685]"

Signed-off-by: Matthias Fischer <matthias.fischer@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>