Email notifications are sent at each restart of the server if a Bcc address is configured in Administration

Steps to reproduce

1. Edit xwiki.properties and set notifications.emails.live.graceTime = 1 to enable the sending of e-mails after 1 minute
2. Login as Admin
3. Go to Administer Wiki > Mail > Mail Sending
4. Configure email sending settings including a BCC email address
5. Optional: set "Discard Success Statuses" to No
6. Login as an user (e.g. U1) which has an email address set in his profile
7. Click on Notifications Bell and set all Watch toggles to ON (make sure on Notifications Settings > Applications section the Pages toggles are set to ON for Email column)
8. Set "Email Frequency" to Live
9. Login as Admin or other user
10. Create a page
11. Wait (app 1 min) and confirm that the email notification for the page creation event is received by the user
12. Close and restart the XWiki instance
13. After restart, observe the user's email inbox

Expected results

No email is received, since the email notification for page creation event was received already before the restart of the instance.

Actual results

The email notification is received again.

In Administration > Mail > Mail Sending Status, after every instance restart, the respective mail job sent is listed with the Status "send_success".

Reproduced also on XWiki 15.5.1.