message: replace original event if there have been previous edits
diff: @@ -116,7 +116,7 @@ export default class MessageEditor extends React.Component {
  "body": textSerialize(this.model),
  "m.relates_to": {
  "rel_type": "m.replace",
  - "event_id": this.props.event.getId(),
  + "event_id": this.props.event.getOriginalId(),
  },
  };
  if (requiresHtml(this.model)) {
  