dhtproxy: unify client destruction & shutdown with stop()

include/opendht/dht_proxy_client.h

@@ -277,6 +277,7 @@ private:
      * Start the connection with a server.
      */
     void startProxy();
+    void stop();
 
     /**
      * Get informations from the proxy node

src/dht_proxy_client.cpp

@@ -133,6 +133,12 @@ DhtProxyClient::handleProxyConfirm(const asio::error_code &ec)
 }
 
 DhtProxyClient::~DhtProxyClient()
+{
+    stop();
+}
+
+void
+DhtProxyClient::stop()
 {
     isDestroying_ = true;
     cancelAllOperations();
@@ -200,8 +206,7 @@ DhtProxyClient::cancelAllListeners()
 void
 DhtProxyClient::shutdown(ShutdownCallback cb)
 {
-    cancelAllOperations();
-    cancelAllListeners();
+    stop();
     if (cb)
         cb();
 }