2.13-1 and 2.13-2 install
/etc/apparmor.d/cache.d/CACHEDIR.TAG/apparmor.CACHEDIR.TAG
… while we want /etc/apparmor.d/cache.d/CACHEDIR.TAG instead.

Not sure I've missed it as I'm pretty sure I had tested this carefully
(I suspect I messed up while cleaning up my Git history).