Release with correct list of conffiles

This is just a change to the packaging, not to the actual deployed
contents of the package. This deb has quite a few conffiles which
made unattended-upgrades flag the mistake when I tried to upgrade.

We should now have the right list of conffiles:

makedeb@08d12c3c

ROOT/DEBIAN/control

@@ -3,6 +3,6 @@ Priority: optional
 Section: otherosfs
 Maintainer: Chemistry COs <support@ch.cam.ac.uk>
 Architecture: all
-Version: 0.9-ch79
+Version: 0.9-ch81
 Depends: zfs-dkms, postgresql-13 | postgresql-9.5 | postgresql-9.4 , liblockfile-simple-perl, libdbi-perl, libjson-perl, libzfs-perl-chem, libnet-openssh-perl, libdbd-pg-perl, mbuffer, rsync, nfs-kernel-server, pv, libwww-curl-perl
 Description: a backup system using ZFS (repository 'backup-scheduler')