This will affect new IPFire installations only, implementing a
long-standing BCP for preemptively combating botnet spam. Reject is
chosen over drop to reduce the likelihood for confusion during network
troubleshooting.
Cc: Michael Tremer <michael.tremer@ipfire.org>
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Tested-by: Peter Müller <peter.mueller@ipfire.org>