esp8266/mpconfigport.h: Remove duplicate link to lwip module.

It's already included in the core when MICROPY_PY_LWIP is defined.

esp8266/mpconfigport.h

@@ -161,7 +161,6 @@ extern const struct _mp_obj_module_t onewire_module;
 
 #define MICROPY_PORT_BUILTIN_MODULES \
     { MP_OBJ_NEW_QSTR(MP_QSTR_esp), (mp_obj_t)&esp_module }, \
-    { MP_OBJ_NEW_QSTR(MP_QSTR_lwip), (mp_obj_t)&mp_module_lwip }, \
     { MP_OBJ_NEW_QSTR(MP_QSTR_socket), (mp_obj_t)&mp_module_lwip }, \
     { MP_OBJ_NEW_QSTR(MP_QSTR_usocket), (mp_obj_t)&mp_module_lwip }, \
     { MP_OBJ_NEW_QSTR(MP_QSTR_network), (mp_obj_t)&network_module }, \