Fix squid password prompt

To fix squid authentication we need set permissions in  /var/lib/samba/winbindd_privileged folder:

Set user root and group for winbind:

chown root:proxy /var/lib/samba/winbindd_privileged -R
or
chown root:squid /var/lib/samba/winbindd_privileged -R

Set folder permission
chmod 750 /var/lib/samba/winbindd_privileged -R

and restart winbind and squid

systemctl restart winbind

systemctl restart squid