ICSL value from server-side is never used.

[YuShengwei-95]

Hi, it seems that ICSL value from SHLO hs_ctx->icsl = get_tag_value_i32(val, len); is never used.

set_earliest_idle_alarm always uses conn->fc_settings->es_idle_conn_to instead of referring to the negotiated ICSL value.

If the server does not send a close frame when closing the connection, this will cause the client to think that the connection is still available, but will not actually receive any data from sever side.

[litespeedtech]

that's for gQUIC, not the latest IETF QUIC/HTTP3.