Merge pull request #3464 from matrix-org/hawkowl/isort-run

changelog.d/3464.misc

synapse/api/auth.py

synapse/api/errors.py

synapse/api/filtering.py

synapse/api/urls.py

synapse/app/__init__.py

synapse/app/_base.py

synapse/app/appservice.py

synapse/app/client_reader.py

synapse/app/event_creator.py

synapse/app/federation_reader.py

synapse/app/federation_sender.py

synapse/app/frontend_proxy.py

synapse/app/homeserver.py

synapse/app/media_repository.py

synapse/app/pusher.py

synapse/app/synchrotron.py

synapse/app/synctl.py

synapse/app/user_dir.py

synapse/appservice/__init__.py