package/ntp: security bump to version 4.2.8p14

package/ntp: security bump to version 4.2.8p14

"This release fixes three security issues in ntpd and provides 46
bugfixes and addresses 4 other issues." [1]

NONE: Sec 3610: process_control() should bail earlier on short packets.

MEDIUM: Sec 3596: Unauthenticated ntpd may be susceptible to IPv4 spoof
attack from highly predictable transmit timestamps.

MEDIUM: Sec 3592: DoS Attack on unauthenticated client.
The fix for https://bugs.ntp.org/3445 introduced a bug whereby a system that
is running ntp-4.2.8p12 (possibly earlier) or p13 that only has one
unauthenticated time source can be attacked in a way that causes the
victim's next poll to its source to be delayed, for as long as the attack is
maintained.

[1] http://support.ntp.org/bin/view/Main/SecurityNotice#March_2020_ntp_4_2_8p14_NTP_Rele

The copyright year has changed in the COPYRIGHT file, so adjust the hash to
match and adjust the spacing to match recent agreements:

@@ -3,7 +3,7 @@

    jpg "Clone me," says Dolly sheepishly.

-   Last update: 2-Jan-2017 11:58 UTC
+   Last update: 4-Feb-2020 23:47 UTC
      __________________________________________________________________

    The following copyright notice applies to all files collectively called
@@ -32,7 +32,7 @@
    Burnicki is:
 ***********************************************************************
 *                                                                     *
-* Copyright (c) Network Time Foundation 2011-2017                     *
+* Copyright (c) Network Time Foundation 2011-2020                     *
 *                                                                     *
 * All Rights Reserved                                                 *
 *                                                                     *

Signed-off-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
[Peter: clarify security impact, document COPYRIGHT change]
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>