MQTT_EVENT_UNSUBSCRIBED has a additional context: msg_id! (IDFGH-7950)

[liang-zhu-zi]

MQTT_EVENT_UNSUBSCRIBED 的注释如下：

typedef enum esp_mqtt_event_id_t {
    ...
    MQTT_EVENT_UNSUBSCRIBED, /*!< unsubscribed event */
    ...
} esp_mqtt_event_id_t;

但实际上， MQTT_EVENT_UNSUBSCRIBED 有一个 msg_id 的附加内容，应修改其注释如下：

typedef enum esp_mqtt_event_id_t {
    ...
    MQTT_EVENT_UNSUBSCRIBED, /*!< unsubscribed event, additional context:  msg_id */
    ...
} esp_mqtt_event_id_t;

[david-cermak]

@liang-zhu-zi Good point, thanks for noticing! Please feel free to file a PR with this update of documentation. will be happy to accept it and merge. (otherwise, will fix later)