gnupg: security bump to version 1.4.21

Fixes CVE-2016-6313: An attacker who obtains 580 bytes from the standard RNG
can trivially predict the next 20 bytes of output.

Add cryptographically secure sha256 hash.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/gnupg/gnupg.hash

@@ -1,2 +1,4 @@
-# From https://lists.gnupg.org/pipermail/gnupg-announce/2015q4/000382.html
-sha1	cbc9d960e3d8488c32675019a79fbfbf8680387e	gnupg-1.4.20.tar.bz2
+# From https://lists.gnu.org/archive/html/info-gnu/2016-08/msg00008.html
+sha1	e3bdb585026f752ae91360f45c28e76e4a15d338	gnupg-1.4.21.tar.bz2
+# Locally computed
+sha256	6b47a3100c857dcab3c60e6152e56a997f2c7862c1b8b2b25adf3884a1ae2276	gnupg-1.4.21.tar.bz2

package/gnupg/gnupg.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-GNUPG_VERSION = 1.4.20
+GNUPG_VERSION = 1.4.21
 GNUPG_SOURCE = gnupg-$(GNUPG_VERSION).tar.bz2
 GNUPG_SITE = ftp://ftp.gnupg.org/gcrypt/gnupg
 GNUPG_LICENSE = GPLv3+