Core Update 157: Ship backup package to apply changed permissions

Core Update 157: Ship backup package to apply changed permissions

This is required as "backup" itself does not gets updated automatically,
contrary to it's LFS file suggesting by having a "PAK_VER" number.

In order to fix #12619, it is therefore necessary to ship the backup
files with Core Update 157.

Partially fixes: #12619

Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>