update registration failure log

kamailio/registrar-role.cfg

@@ -80,7 +80,7 @@ route[HANDLE_REGISTER]
                     #!endif
 
                     auth_challenge("$fd", "0");
-                    xlog("L_INFO", "$ci|end|issued new auth challenge to failed registration attempt");
+                    xlog("L_INFO", "$ci|end|failed registration attempt from $si:$sp for $Au");
                     exit;
                 } else {
                     xlog("L_DBG", "$ci|log|caching SIP credentials for $Au");