ntlm: copy NTLM_HOSTNAME to host buffer

Commit 709ae2454f added a fake hostname to avoid leaking the local
hostname, but omitted copying it to the host buffer.  Fix by copying
and adjust the test fallout.

Closes: #8895
Fixes: #8893
Reported-by: Patrick Monnerat <patrick@monnerat.net>
Reviewed-by: Daniel Stenberg <daniel@haxx.se>

lib/vauth/ntlm.c

@@ -536,6 +536,7 @@ CURLcode Curl_auth_create_ntlm_type3_message(struct Curl_easy *data,
     hostlen = strlen(host);
   }
 #else
+  msnprintf(host, sizeof(host), "%s", NTLM_HOSTNAME);
   hostlen = sizeof(NTLM_HOSTNAME)-1;
 #endif