Fix some typos.

synapse/config/auth.py

synapse/config/room_directory.py

synapse/handlers/room.py

synapse/push/bulk_push_rule_evaluator.py

synapse/rest/admin/users.py

synapse/rest/client/v2_alpha/room_upgrade_rest_servlet.py

synapse/rest/media/v1/_base.py

synapse/rest/media/v1/media_repository.py

synapse/state/__init__.py

synapse/storage/databases/main/deviceinbox.py

synapse/storage/databases/main/event_federation.py

synapse/storage/databases/main/events.py

synapse/storage/databases/main/keys.py

synapse/storage/databases/main/metrics.py

synapse/storage/databases/main/receipts.py

synapse/storage/databases/main/room.py

synapse/storage/databases/main/state_deltas.py

synapse/storage/databases/main/transactions.py

synapse/storage/databases/state/bg_updates.py

synapse/storage/prepare_database.py