package/samba4: AD DC support needs ADS

Needed due to upstream commit:
https://gitlab.com/samba-team/samba/-/commit/607c9ab307db36aee0604d209a13b45d28c63d9b

Fixes:
http://autobuild.buildroot.net/results/b3f/b3fe797408b9041de37433602b3a47211818e44b/



Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>