message: try to make joining rooms more obvious
diff: @@ -146,7 +146,7 @@ module.exports = React.createClass({
  <div>
  <div className="mx_RoomPreviewBar_join_text">
  You are trying to access { name }.<br/>
  - Would you like to <a onClick={ this.props.onJoinClick }>join</a> in order to participate in the discussion?
  + <a onClick={ this.props.onJoinClick }>Click here to join</a> the discussion!
  </div>
  </div>
  );
  