Add default value for mail_notification in site.system config

Okay, the tests are passed. Let's see if the changes will fit.

Thanks! But will need an upgrade path for existing sites.

All tests are passed.

Thanks! But think in the update we should check if the value is set first. This current update could undo someones setting. So if the value is set we can leave alone, if not set a default.

Thanks for noticing that. You are totally right @smustgrave, I just missed that thing. That's why I don't like to work at night ;)

Let's check if the tests will pass.

Tests are all green.

Hi.
Are more changes needed here?

Fixed changes after the last comment. All tests are passed.
But, I don't know why it shows so many changes, I just pulled changes from the 11.x branch.

Ok, now it looks better =)

Feedback and moving to system post_update hook seems to have been addressed.

Updated MR.

Fixed the issue summary to not include TBD and NA for proposed solution.

This was previously missed in #2379683: Fix configuration schema issues in contact (indirectly user and system) modules → and originally introduced in ✨ Allow for custom user registration approval email address Fixed .

I ran into this same problem in 📌 [PP-1] Configuration schema & required keys Needs review .

Committed 4f633dc and pushed to 11.x. Thanks!

Not backportable due to the update hook.

Automatically closed - issue fixed for 2 weeks with no activity.