turn off LWIP_DEBUG

modules/Ethernet/lwipopts.h

@@ -246,7 +246,7 @@ The STM32F4x7 allows computing and verifying the IP, UDP, TCP and ICMP checksums
    -----------------------------------
 */
 
-#define LWIP_DEBUG
+//#define LWIP_DEBUG
 
 #define TCP_DEBUG                       LWIP_DBG_OFF
 #define ETHARP_DEBUG                    LWIP_DBG_OFF