python-cryptography: update to latest version

This version fixes a compilation error when used with OpenSSL 1.0.2g
(https://github.com/pyca/cryptography/issues/2750).

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

lang/python-cryptography/Makefile

@@ -1,5 +1,5 @@
 #
-# Copyright (C) 2015 OpenWrt.org
+# Copyright (C) 2015-2016 OpenWrt.org
 #
 # This is free software, licensed under the GNU General Public License v2.
 # See /LICENSE for more information.
@@ -8,12 +8,12 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=cryptography
-PKG_VERSION:=1.2.2
+PKG_VERSION:=1.2.3
 PKG_RELEASE:=1
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://pypi.python.org/packages/source/c/cryptography
-PKG_MD5SUM:=2b25eebd1d3c6bae52b46f0dcec74dfb
+PKG_MD5SUM:=5474d2b3e8c7555a60852e48d2743f85
 
 PKG_BUILD_DEPENDS:=python-cffi/host