Refresh debian/not-installed

/etc/default/zfs and /etc/zfs/zfs-functions are now installed by the
makefiles.  Continue to install them directly as before, but do not
--fail-missing because of them.

adapted from debian-upstream [0] commit
9a594875114fe186aebba2776b14817ab7f272ae

[0] https://salsa.debian.org/zfsonlinux-team/zfs.git

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>

debian/not-installed

@@ -1,5 +1,6 @@
 usr/share/zfs/enum-extract.pl
 usr/share/zfs/zfs-helpers.sh
+etc/default/zfs
 etc/init.d
 etc/sudoers.d
 etc/zfs/vdev_id.conf.alias.example
@@ -9,3 +10,4 @@ etc/zfs/vdev_id.conf.sas_switch.example
 etc/zfs/vdev_id.conf.scsi.example
 usr/lib/dracut
 usr/share/zfs/enum-extract.pl
+etc/zfs/zfs-functions