Fix sql error in _get_state_groups_from_groups
Fix sql error in _get_state_groups_from_groups

If this was called with a `(type, None)` entry in types (which is supposed to
return all state of type `type`), it would explode with a sql error.

matrix-org/synapse,matrix-org/synapse,matrix-org/synapse,matrix-org/synapse,matrix-org/synapse,matrix-org/synapse