Fix comment: we don't use AppArmor rewrite rules, but aliases.

Both exist :)

features/evince.feature

@@ -35,7 +35,7 @@ Feature: Using Evince
     Then I see "EvinceUnableToOpen.png" after at most 10 seconds
     And AppArmor has denied "/usr/bin/evince" from opening "/lib/live/mount/overlay/home/amnesia/.gnupg/default-testpage.pdf"
     When I close Evince
-    # Due to our AppArmor rewriting rules, /live/overlay will be treated
+    # Due to our AppArmor aliases, /live/overlay will be treated
     # as /lib/live/mount/overlay. We have to clear syslog we'll look for
     # the same entry as above again.
     Given I clear syslog