package/samba4: bump version to 4.6.9

Release notes: https://www.samba.org/samba/history/samba-4.6.9.html



Added license hash.

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