use correct lwip options
#pragma once
-#define NO_SYS 2
+#define NO_SYS 1
+#define LWIP_SOCKET 0
+#define LWIP_NETCONN 0
#ifdef LWIP_DEBUG
#define LWIP_PLATFORM_DIAG(x) do {lwip_debug x;} while(0)
#define LWIP_DBG_MIN_LEVEL LWIP_DBG_LEVEL_ALL
