libidn: bump to version 1.31

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/libidn/libidn.hash

@@ -1,2 +1,2 @@
-# From http://lists.gnu.org/archive/html/help-libidn/2015-03/msg00001.html
-sha1	557e1e37f0978e975b21bcdc243c198cb708bb75	libidn-1.30.tar.gz
+# From http://lists.gnu.org/archive/html/help-libidn/2015-07/msg00011.html
+sha1	0bb34003a0fe05a91e60d346803401f16c82a1fb	libidn-1.31.tar.gz

package/libidn/libidn.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-LIBIDN_VERSION = 1.30
+LIBIDN_VERSION = 1.31
 LIBIDN_SITE = $(BR2_GNU_MIRROR)/libidn
 LIBIDN_INSTALL_STAGING = YES
 LIBIDN_CONF_ENV = EMACS="no"