[Samba] Almost all print driver uploads fail

[Egerváry Gergely]

Okay, so I have successfully fixed this one.

The main rule: never ever set `spoolss: os_major' and `oss_minor'. It 
fixes some drivers, but brokes all others.
The second rule: restarting the `smbd' process on configuration change 
is not enough. You have to kill/restart all rpcd_* services, like 
`rpcd_spoolss'.
The third rule: always clean up and double check all permissions, 
idmaps, etc.

Thank you for your support.

> Hi,
>
> I'm working on a minimal print server setup for Windows 10/11 x64 
> clients.
> No domain, no Kerberos, no LDAP, only a few local users on a 
> standalone server with some shared CUPS printers.
> Printing works well.
>
> After setting 'spoolss: os_major = 6' and 'spoolss: os_minor = 1' The 
> *Kyocera KX Universal Driver* has uploaded well. But, that's all.
>
> No success uploading other print drivers, like *HP Universal Printing 
> PCL6* and *Canon Generic Plus PCL6
> *All of them are failing with messages like:
>
>    "Unable to install HP Universal Printing PCL 6, Type 3 - User Mode,
>    x64 driver."
>    This operation is not supported
>
> and
>
>    "Unable to install Canon Generic Plus PCL6, Type 3 - User Mode, x64
>    driver."
>    This operation is not supported