change MEMP_NUM_NETBUF = 2

modules/Ethernet/lwipopts.h

@@ -103,7 +103,7 @@ a lot of data that needs to be copied, this should be set high. */
  * (only needed if you use the sequential API, like api_lib.c)
  */
 
-#define MEMP_NUM_NETBUF                 7
+//#define MEMP_NUM_NETBUF                 7
 
 
 /* ---------- TCP options ---------- */