[Tails-dev] [review'n'merge:1.4] bugfix/9370-AppArmor-harden…

Hi,

this branch fixes a hole in Pidgin (and possibly other apps) AppArmor
confinement, discovered thanks to the ongoing audit of our AppArmor
policy (#8007). Kill Your TV has run the relevant automated tests and
they pass. Please review'n'merge, and very sorry for the last
minute notice.

Cheers,
--
intrigeri