ctdb-server: Rename CTDB_BROADCAST_VNNMAP -> CTDB_BROADCAST_ACTIVE

ctdb-server: Rename CTDB_BROADCAST_VNNMAP -> CTDB_BROADCAST_ACTIVE

This broadcast is misnamed.  Both places where this type of broadcast
is used expect the broadcast to go to all active nodes.

Make the corresponding change to the semantics in the daemon by
sending to all active nodes.

There is a mismatch between the ideas of VNN map and active nodes.  A
node that is not in the VNN map but is active can still host database
records.  These were the same until the LMASTER capability was
introduced and then the logic was not updated.

The only place where the VNN map is relevant is when finding the
location master of a record in the migration code.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13499

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>
(cherry picked from commit 36938bfdd075a174daecb466085702adfe6a6c09)