Code review comment for lp:~michihenning/thumbnailer/config-access

Related branch for the apparmor profile update:

https://code.launchpad.net/~michihenning/apparmor-easyprof-ubuntu/new-thumbnailer-methods/+merge/281712

Note that this change can land regardless. If apparmor denies access, we use the defaults, so it'll magically work once apparmor catches up.