bind: Update to 9.16.49

bind: Update to 9.16.49

For details see:
https://downloads.isc.org/isc/bind9/9.16.49/doc/arm/html/notes.html#notes-for-bind-9-16-49

"Bug Fixes

    A regression in cache-cleaning code enabled memory use to grow
    significantly more quickly than before, until the configured
    max-cache-size limit was reached. This has been fixed. [GL #4596]

    Using rndc flush inadvertently caused cache cleaning to become
    less effective. This could ultimately lead to the configured
    max-cache-size limit being exceeded and has now been fixed. [GL #4621]

    The logic for cleaning up expired cached DNS records was tweaked to be
    more aggressive. This change helps with enforcing max-cache-ttl and
    max-ncache-ttl in a timely manner. [GL #4591]

    It was possible to trigger a use-after-free assertion when the overmem
    cache cleaning was initiated. This has been fixed. [GL #4595]"

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