Summary:
When the ACL page was visited by an anonymous user (for a temporary doc), it
tried to load the "View as" list, which failed. Apart from example users, it was
also trying to load all users the document is shared with by checking the home db.
However, since the document is not persisted, it failed.
Test Plan: Added new test
Reviewers: Spoffy
Reviewed By: Spoffy
Subscribers: Spoffy
Differential Revision: https://phab.getgrist.com/D4257