Start Timer T3 when starting Timer T1 after expiry

Start Timer T3 when starting Timer T1 after expiry, to avoid a situation
wherein two RR command polling frames may be sent within close proximity
of one another

src/server.c

@@ -2164,6 +2164,7 @@ static int handle_sock(uint32_t key,
 
                     sock->retries--;
                     patty_timer_start(&sock->timer_t1);
+                    patty_timer_start(&sock->timer_t3);
 
                     return ret;
                 } else {