tldap: Receiving "msgid == 0" means the connection is dead

tldap: Receiving "msgid == 0" means the connection is dead

We never use msgid=0, see tldap_next_msgid(). RFC4511 section 4.4.1
says that the unsolicited disconnect response uses msgid 0. We don't
parse this message, which supposedly is an extended response: Windows
up to 2019 sends an extended response in an ASN.1 encoding that does
not match RFC4511.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=14465

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Fri Aug 21 20:37:25 UTC 2020 on sn-devel-184

(cherry picked from commit ccaf661f7c75717341140e3fbfb2a48f96ea952c)

Autobuild-User(v4-12-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-12-test): Mon Aug 31 10:51:57 UTC 2020 on sn-devel-184