s3:net: disable dynamic dns updates at the end of "net ads join" in a cluster (bug...

s3:net: disable dynamic dns updates at the end of "net ads join" in a cluster (bug #7871)

In a clustered environment, registering the set of ip addresses that are
assigned to the interfaces of the node that performs the join does usually
not have the desired effect, since the local interfaces do not carry
complete set of the cluster's public IP addresses.  And it can also contain
internal addresses that should not be visible to the outside at all.
In order to do dns updates in a clustererd setup, use net ads dns register.

This fixes the net ads join part of bug #7871.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
(cherry picked from commit b8f19df53e66bf0260b4ae6c49acea87ac379deb)