[Samba] Sonos S1 access denied with Samba 4.17

[James Youngman]

I set

   server min protocol = NT1
   client min protocol = NT1

in smb.conf.    Then restarting smbd (and likewise for all subsequent
changes).  This did not seem to solve the problem.   At this point I
switched from testing by asking the Sonos unit to play a track from
the share, to re-entering the details of the SMB share where the music
files lived.  That didn't work.  I added an SMB user named "sonos".
That didn't seem to fix the problem.   I added a local OS user also
named "sonos".  That also didn't seem to fix the problem (though in
all these cases it worked from smbclient).

I then changed smb.conf to set

   unix extensions = no

Following that, the Sonos S1 system was able to connect,   I don't
know for sure if this was the important change, or whether things
lurched to life following some earlier change with delayed effect.

James.