[lib] Fix keyserver sending updated RoleInfos to old clients
Summary:
@atul's recent changes caused a major issue where new RoleInfos were being delivered to older clients, causing validation failures.
This diff makes it so keyserver can continue outputting the old-style RoleInfos to current clients.
Test Plan:
I deployed this to prod and:
- Confirmed web app refreshed without issue
- Confirmed web app could log out / back in
- Confirmed native could receive a message without seeing validation errors
- Confirmed native could press a notif without seeing validation errors
- Confirmed native could log out / back in
Reviewers: atul
Reviewed By: atul
Subscribers: tomek, atul
Differential Revision: https://phab.comm.dev/D11496