Fix the wbinfo test on the LDAP backend.

Fix the wbinfo test on the LDAP backend.

The problem was that we would do a blocking wait for the LDAP server,
which was also blocking on us returning (because we were in single
process mode).

The LDAP connection being made here is useless anyway, and will need
to be an async ldb_connect() before anybody reintroucues it (nobody in
their right mind would program a winbindd backend on pure LDAP, when
the ldb abstraction is available).

Andrew Bartlett
(This used to be commit 23280b2e6ed5afb968bf0b8c40febb085eed38a1)