improve clarity of error message in case of wrong proxy server password

why not be real user friendly and tell them where to get the password from and what the exact name of the password is. 
being not helpful just gives tinyproxy a bad name... ;-)

src/reqs.c

@@ -1641,7 +1641,7 @@ void handle_connection (int fd)
                                 failure = 0;
                 if(failure) {
 e401:
-                        update_stats (STAT_DENIED);
+                        update_stats (STAT_DENIED);     
                         indicate_http_error (connptr, 401, "Unauthorized",
                                              "detail",
                                              "The administrator of this proxy has not configured "
@@ -1651,7 +1651,7 @@ void handle_connection (int fd)
                 }
                 hashmap_remove (hashofheaders, "proxy-authorization");
         }
-
+/* above we should try to clarify it to even newbie users that their proxy password is what is wrong most likely here and actually tell him what to do about it. Those succint error msg drive ppl crazy */
         /*
          * Add any user-specified headers (AddHeader directive) to the
          * outgoing HTTP request.