package/samba4: security bump to version 4.6.8

Release notes:
https://www.samba.org/samba/history/samba-4.6.8.html

Fixes
- CVE-2017-12150 (SMB1/2/3 connections may not require signing where
  they should)
- CVE-2017-12151 (SMB3 connections don't keep encryption across DFS
  redirects)
- CVE-2017-12163 (Server memory information leak over SMB1)

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/samba4/samba4.hash

@@ -1,2 +1,2 @@
 # Locally calculated
-sha256 9ef24393de08390f236cabccd6a420b5cea304e959cbf1a99ff317325db3ddfa  samba-4.6.7.tar.gz
+sha256 581deeb2543f5cedcb556cb950d0e82690d9f0cd33811d76624502ca0c32575d  samba-4.6.8.tar.gz

package/samba4/samba4.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-SAMBA4_VERSION = 4.6.7
+SAMBA4_VERSION = 4.6.8
 SAMBA4_SITE = https://download.samba.org/pub/samba/stable
 SAMBA4_SOURCE = samba-$(SAMBA4_VERSION).tar.gz
 SAMBA4_INSTALL_STAGING = YES