d212ec13b8
Synapse does not require the `verify_keys` attr/object to be set. It made sense back in the day, when federation traffic used to use self-signed certificates. But this is no longer the case. The previous `types.nullOr` didn't actually allow omitting `verify_keys` because Synapse's config parser is unable to parse that. Not a breaking change. Upstream docs: https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html?highlight=verify_keys#trusted_key_servers