This option sets the command that is called to apply GPO policies.
The samba-gpupdate script applies System Access and Kerberos Policies
to the KDC. System Access policies set minPwdAge, maxPwdAge,
minPwdLength, and pwdProperties in the samdb. Kerberos Policies set
kdc:service ticket lifetime, kdc:user ticket lifetime, and kdc:renewal
lifetime in smb.conf.
&pathconfig.SCRIPTSBINDIR;/samba-gpupdate
/usr/local/sbin/gpoupdate