strongswan: security bump to version 5.3.1

Fixes:

CVE-2015-3991 - denial-of-service and potential remote code execution
vulnerability triggered by IKEv1/IKEv2 messages that contain payloads
for the respective other IKE version.
other IKE version

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/strongswan/strongswan.hash

@@ -1,2 +1,2 @@
-# From http://download.strongswan.org/strongswan-5.3.0.tar.bz2.md5
-md5	c52d4228231c2025d9c320d0e9990327	strongswan-5.3.0.tar.bz2
+# From http://download.strongswan.org/strongswan-5.3.1.tar.bz2.md5
+md5	66f258901a3d6c271da1a0c7fb3e5013	strongswan-5.3.1.tar.bz2

package/strongswan/strongswan.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-STRONGSWAN_VERSION = 5.3.0
+STRONGSWAN_VERSION = 5.3.1
 STRONGSWAN_SOURCE = strongswan-$(STRONGSWAN_VERSION).tar.bz2
 STRONGSWAN_SITE = http://download.strongswan.org
 STRONGSWAN_LICENSE = GPLv2+