http: Added authentication message header value extraction

...following recent changes to Curl_base64_decode() rather than trying
to parse a header line for the authentication mechanisms which is CRLF
terminated and inline zero terminate it.

lib/curl_ntlm.c

@@ -77,10 +77,6 @@ CURLcode Curl_input_ntlm(struct connectdata *conn,
 
   ntlm = proxy ? &conn->proxyntlm : &conn->ntlm;
 
-  /* skip initial whitespaces */
-  while(*header && ISSPACE(*header))
-    header++;
-
   if(checkprefix("NTLM", header)) {
     header += strlen("NTLM");