s3:utils: Fix the auth function to print correct values to the user

s3:utils: Fix the auth function to print correct values to the user

In order to show correct values in the password prompt displayed by
cli_credentials_get_password*(). We need to set the domain and username
in the credentials system.

The credentials supplied via the SMB URL have a higher priority than the
command line options.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15538

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
(cherry picked from commit 1134c4f3a63c9618c3fb79abefb40a798c7c1701)