Added required "debug" feature, missed in commit 1c9aaa0bac, as NTLMv2
calls Curl_rand() which can only be fixed to a specific entropy in
debug builds.
Previously it only compared credentials if the requested needle
connection wasn't using a proxy. This caused NTLM authentication
failures when using proxies as the authentication code wasn't send on
the connection where the challenge arrived.
Added test 1215 to verify: NTLM server authentication through a proxy
(This is a modified copy of test 67)
