message: Reply should be checking eventContent of previous event
diff: @@ -1543,8 +1543,8 @@ MatrixHandler.prototype._textForReplyEvent = Promise.coroutine(function*(event,
  if (typeof(eventContent.content.body) !== "string") {
  throw Error("'body' was not a string.");
  }
  - const isReply = event.content["m.relates_to"] &&
  - event.content["m.relates_to"]["m.in_reply_to"];
  + const isReply = eventContent.content["m.relates_to"] &&
  + eventContent.content["m.relates_to"]["m.in_reply_to"];
  if (isReply) {
  const sourceMatch = REPLY_REGEX.exec(eventContent.content.body);
  rplSource = sourceMatch.length === 4 ? sourceMatch[3] : event.content.body;
  