message: Clear url previews if they all get edited out of the event
diff: @@ -172,6 +172,8 @@ export default createReactClass({
  const hidden = global.localStorage.getItem("hide_preview_" + this.props.mxEvent.getId());
  this.setState({ widgetHidden: hidden });
  }
  + } else if (this.state.links.length) {
  + this.setState({ links: [] });
  }
  }
  },
  