Net::LDAP with LDAPS connection records empty cassettes

Cassettes are not being recorded when using `Net::LDAP` with an LDAPS connection (I didn't test it with plain LDAP), it only creates cassettes with an empty JSON array. It happens the same when using Marshall format. LDAP tests are only testing that using `Net::LDAP` does not raise an error, but it's not testing that a cassette is actually being recorded. Tested with `net-ldap (0.16.2)`