Avoid slow reverse-DNS requests caused by libwebsocket (#222)

Avoid slow reverse-DNS requests caused by libwebsocket (#222)

* Avoid slow reverse-DNS requests caused by libwebsocket

According to warmcat/libwebsockets#537 and following my own experience, in some circumstances lws_get_peer_addresses can take several seconds to execute a reverse DNS request on a connected peer IP. The effect is that sometimes a websocket connection takes several seconds before it is established.
This PR addresses the described issue by replacing lws_get_peer_addresses with lws_get_peer_simple that completely skips the RDNS request.

Signed-off-by: Xiang Dai <764524258@qq.com>