Affects Version/s: Master
Steps to Reproduce:
1. Create a new group or organization.
2. Create the site and add a public page.
3. Add a Message Boards portlet to the public page.
4. Subscribe to the Message Boards portlet's home folder.
5. Delete the group or organization.
6. Check the Subscription table on the database.
Subscription table has no entries.
Subscription table still has the entry for the Message Boards subscription.
Issue reproduced in branch.
Issue reproduced in master.