r20353: Restructure the DRSUAPI DsGetDomainControllerInfo test, because as

r20353: Restructure the DRSUAPI DsGetDomainControllerInfo test, because as
usual things are more complex than they appear.

Also remove the incorrect server-side implementation, which blindly
assumed some sense of consistancy across the API switch levels.

Andrew Bartlett
(This used to be commit 79941adbff843f5027dacd31b972deca4a1557ec)