Email address is not removed from db after last unsubscription
If an address is not assigned to any lists, the address should be removed from the core database. However tests using version 3.2.1 showed that it stays forever. This also applies to unconfirmed addresses after their pending_request_life. Due to the EU's General Data Protection Regulation (GDPR) this should be avoided.
Steps to reproduce:
- Create a address not known to the database
- Subscribe to a list using the created address
- Unsubscribe the created address from all lists
Actual results:
- Address stays in database
Expected results:
- Address removed from database