fix the display of gflag default values of builtin

src/brpc/builtin/flags_service.cpp

 // Copyright (c) 2015 Baidu, Inc.
-// 
+//
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
-// 
+//
 //     http://www.apache.org/licenses/LICENSE-2.0
-// 
+//
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -17,7 +17,7 @@
 #include <ostream>
 #include <vector>                           // std::vector
 #include <set>
-#include <gflags/gflags.h>                  // GetAllFlags 
+#include <gflags/gflags.h>                  // GetAllFlags
                                             // CommandLineFlagInfo
 #include "butil/string_printf.h"
 #include "butil/string_splitter.h"
@@ -89,7 +89,7 @@ static void PrintFlag(std::ostream& os, const GFLAGS_NS::CommandLineFlagInfo& fl
         if (flag.default_value != flag.current_value) {
             os << " (default:" << (use_html ?
                                    HtmlReplace(flag.default_value) :
-                                   flag.current_value) << ')';
+                                   flag.default_value) << ')';
         }
         if (use_html) {
             os << "</span>";