Don't make potential AppArmor deny logs about @{PROC}/[0-9]*/task/** and @{PROC}...

Don't make potential AppArmor deny logs about @{PROC}/[0-9]*/task/** and @{PROC}/[0-9]*/fd/ silent.

These deny rules were added, without any explanation, in commit 04b24660.

I've never seen Firefox try to break these rules. If someone sees that, then I'm
happy to see the corresponding logs, and then we can research whether the
consequences of letting Firefox access this file are any worse than the
consequences of blocking this access.