package/openvpn: bump version to 2.6.13

Release notes:
https://sourceforge.net/p/openvpn/mailman/message/59119248/

Changelog:
https://github.com/OpenVPN/openvpn/blob/release/2.6/ChangeLog
https://github.com/OpenVPN/openvpn/blob/release/2.6/Changes.rst

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Julien Olivain <ju.o@free.fr>

package/openvpn/openvpn.hash

@@ -1,3 +1,3 @@
 # Locally calculated after checking signature
-sha256  1c610fddeb686e34f1367c347e027e418e07523a10f4d8ce4a2c2af2f61a1929  openvpn-2.6.12.tar.gz
+sha256  1af10b86922bd7c99827cc0f151dfe9684337b8e5ebdb397539172841ac24a6a  openvpn-2.6.13.tar.gz
 sha256  1fcb78d7e478bb8a9408010bdc91b36e213b1facfad093df3f7ce7e28af19043  COPYRIGHT.GPL

package/openvpn/openvpn.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-OPENVPN_VERSION = 2.6.12
+OPENVPN_VERSION = 2.6.13
 OPENVPN_SITE = https://swupdate.openvpn.net/community/releases
 OPENVPN_DEPENDENCIES = host-pkgconf libcap-ng
 OPENVPN_LICENSE = GPL-2.0