windows listen for pollhup

After Ondraco

https://github.com/warmcat/libwebsockets/issues/441



Signed-off-by: Andy Green <andy.green@linaro.org>

changelog

@@ -36,6 +36,8 @@ to tell if more headers had arrived.  Result was if the browser didn't
 close the keepalive, we retained ah for the lifetime of the keepalive,
 using up the pool.
 
+8) MAJOR windows-only-POLLHUP was not coming
+
 
 Changes
 -------

lib/lws-plat-win.c

@@ -387,7 +387,8 @@ lws_plat_insert_socket_into_fds(struct lws_context *context, struct lws *wsi)
 
 	pt->fds[pt->fds_count++].revents = 0;
 	pt->events[pt->fds_count] = WSACreateEvent();
-	WSAEventSelect(wsi->sock, pt->events[pt->fds_count], LWS_POLLIN);
+	WSAEventSelect(wsi->sock, pt->events[pt->fds_count],
+		       LWS_POLLIN | LWS_POLLHUP);
 }
 
 LWS_VISIBLE void