fix wizard test, adjust to changed parameters of the tested method, intr...

...oduced by 9caa354cfc1f73159f335646ca89be4db72b125e

Due to simplification of the method, one parameter was removed in its declaration. The test method should not send it now, obviously.

Affects stable6 only (because i missed to port https://github.com/owncloud/core/pull/8623 -.-)

To test, run test apps/user_ldap/tests/wizard.php

Before it will fail, now it full succeed.

@craigpg @Xenopathic @DeepDiver1975 

@karlitschek: Needs to be ported to stable7 and master together with #8623 subsequently.