package/bind: update to 9.18.31

See here for a changelog:
https://downloads.isc.org/isc/bind9/9.18.31/doc/arm/html/notes.html#notes-for-bind-9-18-31

Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/bind/bind.hash

@@ -1,4 +1,4 @@
-# Verified from https://ftp.isc.org/isc/bind9/9.18.30/bind-9.18.30.tar.xz.asc
+# Verified from https://ftp.isc.org/isc/bind9/9.18.31/bind-9.18.31.tar.xz.asc
 # with key 706B6C28620E76F91D11F7DF510A642A06C52CEC
-sha256  9f6817640970267317e5aa143ecf70531040f2155636b1a63ea45379aa09034a  bind-9.18.30.tar.xz
+sha256  51b258969275c5206ef745a5aac03dbe98f1c8031fefed378d53597e7987b1b3  bind-9.18.31.tar.xz
 sha256  9734825d67a3ac967b2c2f7c9a83c9e5db1c2474dbe9599157c3a4188749ebd4  COPYRIGHT

package/bind/bind.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-BIND_VERSION = 9.18.30
+BIND_VERSION = 9.18.31
 BIND_SOURCE= bind-$(BIND_VERSION).tar.xz
 BIND_SITE = https://ftp.isc.org/isc/bind9/$(BIND_VERSION)
 # bind does not support parallel builds.