PortalSession: If portal is closed, raise error
Emitting error if portal gets closed will clean up everything nicely, instead of leaving a frozen server and frozen video stream for client.
(cherry picked from commit 9720a5dd)
14048e68 PortalSession: If portal is closed, raise error 757a30d4 Add warning
Co-authored-by: Akseli Lahtinen akselmo@akselmo.dev