esp_mqtt_cxx not set last will (IDFGH-12648)

[cubesky]

Answers checklist.

• [X] I have read the documentation for esp-protocols components and the issue is not addressed there.
• [X] I have updated my esp-protocols branch (master or release) to the latest version and checked that the issue is present there.
• [X] I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

I'm using espressif/esp_mqtt_cxx: "^0.3.0" in managed_components. I set the last will with following struct, but it not work.

static idf::mqtt::Configuration config = {
        .session = {
            .last_will = {
                .lwt_topic = willTopic,
                .lwt_msg = willData,
                .lwt_qos = (int)idf::mqtt::QoS::AtLeastOnce,
                .lwt_retain = (int)idf::mqtt::Retain::Retained
            },
            .keepalive = 10,
            .disable_keepalive = false
        }
};

It seems it missing config on this method.

https://github.com/espressif/esp-protocols/blob/master/components/esp_mqtt_cxx/esp_mqtt_cxx.cpp#L135

When I manually add these line in this method, will message work.

mqtt_client_cfg.session.last_will.topic = config.session.last_will.lwt_topic;
mqtt_client_cfg.session.last_will.msg = config.session.last_will.lwt_msg;
mqtt_client_cfg.session.last_will.qos = config.session.last_will.lwt_qos;
mqtt_client_cfg.session.last_will.retain = config.session.last_will.lwt_retain;
mqtt_client_cfg.session.last_will.msg_len = config.session.last_will.lwt_msg_len;
mqtt_client_cfg.session.disable_keepalive = config.session.disable_keepalive;
mqtt_client_cfg.session.keepalive = config.session.keepalive;