Add Fake Packet maximum TTL limit to Auto TTL mode

This patchset adds maximum TTL size of the fake packet to be sent,
to further  improve compatibility with asymmertic routing and
non-standard TTL value set on servers.

src/ttltrack.h

@@ -22,5 +22,6 @@ int tcp_handle_outgoing(uint32_t srcip[4], uint32_t dstip[4],
                         uint8_t is_ipv6);
 
 int tcp_get_auto_ttl(const uint8_t ttl, const uint8_t autottl1,
-                     const uint8_t autottl2, const uint8_t minhops);
+                     const uint8_t autottl2, const uint8_t minhops,
+                     const uint8_t maxttl);
 #endif