rpcd: With npa->need_idle_server we can have more than 256 servers

rpcd: With npa->need_idle_server we can have more than 256 servers

Before this patch the worker-status cut the worker index such that
samba-dcerpcd could not properly update status of the surplus rpc
daemons. This could lead to those daemons to stay around forever,
samba-dcerpcd will never notice they are idle and can exit.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15310

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Mon Mar  6 22:35:00 UTC 2023 on atb-devel-224