Fix: Remove arpa/inet.h from test_nat_engine.c, use platform_compat.h for byte-order funcs

tests/test_nat_engine.c

@@ -11,7 +11,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <arpa/inet.h>
 #include "../lib/debug_config.h"
 #include "../src/eim_nat.h"
 #include "../src/etcp.h"