drsblobs.idl: supplementalCredentialsSubBlob make it possible to parse strange blobs

drsblobs.idl: supplementalCredentialsSubBlob make it possible to parse strange blobs

Windows omits the uint16 num_packages field when the packages array is empty.
This happens if the UF_SMARTCARD_REQUIRED flag is set for an account.

A user was created with a password and then userAccountControl was changed to
UF_NORMAL_ACCOUNT|UF_SMARTCARD_REQUIRED. In that case I'm getting
(as the whole supplementalCredentialsBlob):

[0000] 00 00 00 00 62 00 00 00   00 00 00 00 20 00 20 00   ....b... .... . .
[0010] 20 00 20 00 20 00 20 00   20 00 20 00 20 00 20 00    . . . .  . . . .
[0020] 20 00 20 00 20 00 20 00   20 00 20 00 20 00 20 00    . . . .  . . . .
[0030] 20 00 20 00 20 00 20 00   20 00 20 00 20 00 20 00    . . . .  . . . .
[0040] 20 00 20 00 20 00 20 00   20 00 20 00 20 00 20 00    . . . .  . . . .
[0050] 20 00 20 00 20 00 20 00   20 00 20 00 20 00 20 00    . . . .  . . . .
[0060] 20 00 20 00 20 00 20 00   20 00 20 00 50 00 30       . . . .  . .P.0

I've also got cases (where I created an account with
UF_NORMAL_ACCOUNT|UF_ACCOUNTDISABLE|UF_SMARTCARD_REQUIRED
in the LDAP add) with the following strange blobs:

One time:
[0000] 00 00 00 00 00 00 00 00   00 00 00 00 00
and once:
[0000] 00 00 00 00 00 00 00 00   00 00 00 00 53

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11441

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Günther Deschner <gd@samba.org>