Refresh_certificates_task_interval parameter in ACME client configuration now

Why it matters

This change standardizes the time unit for the refresh_certificates_task_interval parameter to seconds, improving clarity and precision in configuring certificate refresh intervals for the ACME client.

How to use it

When configuring the ACME client, specify the refresh_certificates_task_interval parameter with an integer value representing the interval duration in seconds, for example:

refresh_certificates_task_interval: 3600