message: Show spinner until first sync has completed
  Shows the 'forward paginating' spinner until the first sync has
  completed.
  Fixes
diff: @@ -1058,11 +1058,18 @@ var TimelinePanel = React.createClass({
  // events when viewing historical messages, we get stuck in a loop
  // of paginating our way through the entire history of the room.
  var stickyBottom = !this._timelineWindow.canPaginate(EventTimeline.FORWARDS);
  +
  + // If the state is PREPARED, we're still waiting for the js-sdk to sync with
  + // the HS and fetch the latest events, so we are effectively forward paginating.
  + const forwardPaginating = (
  + this.state.forwardPaginating || MatrixClientPeg.get().getSyncState() == 'PREPARED'
  + );
  +
  return (
  <MessagePanel ref="messagePanel"
  hidden={ this.props.hidden }
  backPaginating={ this.state.backPaginating }
  - forwardPaginating={ this.state.forwardPaginating }
  + forwardPaginating={ forwardPaginating }
  events={ this.state.events }
  highlightedEventId={ this.props.highlightedEventId }
  readMarkerEventId={ this.state.readMarkerEventId }
  