sysctl: For the sake of completeness, do not accept IPv6 redirects
While IPFire 2.x' web interface does not support IPv6, users can
technically run it with IPv6 by conducting the necessary configuration
changes manually.
To provide these systems as well, we should disable acceptance of ICMPv6
redirect packets - which is apparently not default in Linux, yet. :-/
Signed-off-by: Peter Müller <peter.mueller@ipfire.org> Reviewed-by: Michael Tremer <michael.tremer@ipfire.org>