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

(cherry picked from commit a1780ed8d1b46e4760319b27a4978e7ce7a1df80)

Autobuild-User(v4-17-test): Jule Anger <janger@samba.org>
Autobuild-Date(v4-17-test): Tue Mar  7 11:16:46 UTC 2023 on sn-devel-184