HTTPServer: generate sequential Ids for each newly accepted connection

Co-authored-by: Vasil Dimov <vd@FreeBSD.org>

src/httpserver.cpp

@@ -1008,4 +1008,9 @@ std::unique_ptr<Sock> HTTPServer::AcceptConnection(const Sock& listen_sock, CSer
 
     return sock;
 }
+
+HTTPServer::Id HTTPServer::GetNewId()
+{
+    return m_next_id.fetch_add(1, std::memory_order_relaxed);
+}
 } // namespace http_bitcoin