Fixed DHT bind address and converted to using sockaddr.

src/core/dht_manager.h

@@ -10,6 +10,9 @@ class DhtManager {
 public:
   ~DhtManager();
 
+  uint16_t            port() const                 { return m_port; }
+  void                set_port(uint16_t port);
+
   void                load_dht_cache();
   void                save_dht_cache();
   torrent::Object     dht_statistics();
@@ -48,6 +51,8 @@ private:
   bool                m_warned{};
 
   int                 m_start{dht_off};
+  uint16_t            m_port{0};
+
   std::string         m_throttleName;
 };