Fix phrasing.

config/chroot_local-includes/usr/local/sbin/tails-debugging-info

@@ -38,7 +38,7 @@ debug_command grep spoof-mac: /var/log/messages
 #   file, its dir and the parent dirs). From now on let's assume it is
 #   the case and call it $USER.
 #
-# * if any non-root group is has write access, it must not have any
+# * if any non-root group has write access, it must not have any
 #   members.
 #
 # If any of these rules does not apply, the file cannot be added here