message: only clear reply_to_event if there was one to begin with
diff: @@ -867,7 +867,6 @@ export default class MessageComposerInput extends React.Component {
  }
  content.body = nestedReply.body + content.body;
  }
  - }
  // Clear reply_to_event as we put the message into the queue
  // if the send fails, retry will handle resending.
  @@ -875,6 +874,8 @@ export default class MessageComposerInput extends React.Component {
  action: 'reply_to_event',
  event: null,
  });
  + }
  +
  this.client.sendMessage(this.props.room.roomId, content).done((res) => {
  dis.dispatch({
  