Regarding mqtt CONFIG_OUTBOX_EXPIRED_TIMEOUT_MS default value change

[axellin]

Hi,
I notice in the older esp-mqtt version, the default OUTBOX_EXPIRED_TIMEOUT_MS was 30*1000.
commit bdadd77c6e24 ("mqtt: deleted expired messages even when offline") added CONFIG_OUTBOX_EXPIRED_TIMEOUT_MS
so it can be user configureable. However, in 0ea20bed439d ("MQTT: add configurable msg expired timeout"),
the default value for the MQTT_OUTBOX_EXPIRED_TIMEOUT_MS becomes 300000.

My question: Is this default value change from 30 seconds to 5 minutes intentional? Or it's actually a typo?
I'm also curious how to decide the proper OUTBOX_EXPIRED_TIMEOUT_MS to set.