Fix the auth code to enable us to i.e set DIGEST and then find out that the

server doesn't require any auth at all and then we just continue nicely. We
now have an extra bit in the connection struct named 'authprobe' that is TRUE
when doing pure "HTTP authentication probing".

lib/urldata.h

@@ -319,6 +319,9 @@ struct ConnectBits {
                          This is implicit when SSL-protocols are used through
                          proxies, but can also be enabled explicitly by
                          apps */
+  bool authprobe;     /* set TRUE when this transfer is done to probe for auth
+                         types, as when asking for "any" type when speaking
+                         HTTP */
 };
 
 struct hostname {