lib/cmdline: Also redact --newpassword in samba_cmdline_burn()

lib/cmdline: Also redact --newpassword in samba_cmdline_burn()

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15289

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Fri Jul 21 06:16:30 UTC 2023 on atb-devel-224

(cherry picked from commit 76ad44f446c42832e87b2c60a4731a8de3a0018f)

RN: post-exec password redaction for samba-tool is more reliable for
 fully random passwords as it no longer uses regular expressions
 containing the password value itself.

Autobuild-User(v4-18-test): Jule Anger <janger@samba.org>
Autobuild-Date(v4-18-test): Fri Aug  4 08:05:00 UTC 2023 on atb-devel-224