bind: update conffiles list

bind: update conffiles list

The previous patches removed a number of conffiles that weren't necessary,
meaning we can now assume that any changes or additional files in /etc/bind
are things that the user wants to keep.

Since /var/lib/bind is the standard location for longer-lived zone data
(i.e. not zones that secondary servers have obtained via XFER), we symlink
it to /etc/bind/zones so that it survives a sysupgrade.

Temporary files (such as XFER:ed zones for secondaries) stay in
/var/cache/bind.

Signed-off-by: David Härdeman <[email protected]>