message: fix weird `in` op behaviour with null
diff: @@ -137,9 +137,9 @@ export default class Reply extends React.Component {
  if (ev.isRedacted()) return;
  const mRelatesTo = ev.getWireContent()['m.relates_to'];
  - if (mRelatesTo) {
  + if (mRelatesTo && mRelatesTo['m.in_reply_to']) {
  const mInReplyTo = mRelatesTo['m.in_reply_to'];
  - if ('event_id' in mInReplyTo) return mInReplyTo;
  + if (mInReplyTo['event_id']) return mInReplyTo;
  }
  }
  