fix icmp_proxy: write reply to input_queue (not output_queue) to reach TUN device

src/icmp_proxy.c

@@ -258,7 +258,7 @@ int icmp_proxy_deliver_reply(struct UTUN_INSTANCE* inst,
     e->dgram = u_malloc(1 + pkt_len);
     e->dgram[0] = 4; memcpy(e->dgram + 1, pkt, pkt_len); e->len = 1 + pkt_len;
     u_free(pkt);
-    queue_data_put(tun->output_queue, e);
+    queue_data_put(tun->input_queue, e);
     DEBUG_INFO(DEBUG_CATEGORY_SOCKET, "icmp_proxy: reply delivered to TUN id=0x%04x seq=%u", echo_id, echo_seq);
     return 0;
 }