dhtrunner: migrate to SockAddr, use default port if not set

src/node.cpp

@@ -37,6 +37,13 @@ Node::Node(const InfoHash& id, const SockAddr& addr, bool client)
     transaction_id = std::uniform_int_distribution<Tid>{1}(rd);
 }
 
+Node::Node(const InfoHash& id, SockAddr&& addr, bool client)
+: id(id), addr(std::move(addr)), is_client(client), sockets_()
+{
+    thread_local crypto::random_device rd {};
+    transaction_id = std::uniform_int_distribution<Tid>{1}(rd);
+}
+
 /* This is our definition of a known-good node. */
 bool
 Node::isGood(time_point now) const