Description

This commit attempts to clean old strays after some time. Currently, the expiration check is accomplished every time a new connection is made.

Related to issue #846

How to test this

1. Create two or three users named test<n> where n means the amount of minutes before expiration if no new connection is performed
2. Open your favourite browser and use some extension that separates sessions from one tab to another
3. Login with test<n> on a tab
4. use it a little bit then wait n minutes
5. Login with admin on another tab
6. Go back to test<n> tab: the previous "session " of test<n> should be cleaned (the chat history should be empty)

What is missing

Currently, the cleanup and the refresh of sessions happen only when a new connection is done. We need also to refresh the expiration when a user's message arrives. I need some guidance to understand where is the right place to invoke refresh on the code, I think the call should go in some line of

Type of change

• New feature (non-breaking change which adds functionality)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas