another attempt to fix http server crashing problem
it worked in test, hope it works

Change-Id: I452eeb203c96bdcdce642e0ac5f39fb6e03fca6c
diff --git a/server/server.hpp b/server/server.hpp
index d6e50a9..b82088b 100644
--- a/server/server.hpp
+++ b/server/server.hpp
@@ -31,15 +31,16 @@
   explicit server(const std::string& address, const std::string& port,
       const std::string& doc_root);
 
+  ~server();
+
   /// Run the server's io_service loop.
   void run();
 
-  ~server();
-
-private:
   /// Handle a request to stop the server.
   void handle_stop();
 
+private:
+
   /// Initiate an asynchronous accept operation.
   void start_accept();