package/samba4: security bump version to 4.15.5
Release notes: https://www.samba.org/samba/history/samba-4.15.5.html
Fixes CVE-2021-44141, CVE-2021-44142 & CVE-2022-0336.
Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>