message: Fix accepting a 3pid invite
  Fixes
diff: @@ -764,11 +764,13 @@ module.exports = React.createClass({
  // If the user is a ROU, allow them to transition to a PWLU
  if (cli && cli.isGuest()) {
  // Join this room once the user has registered and logged in
  + const signUrl = this.props.thirdPartyInvite ?
  + this.props.thirdPartyInvite.inviteSignUrl : undefined;
  dis.dispatch({
  action: 'do_after_sync_prepared',
  deferred_action: {
  action: 'join_room',
  - room_id: this.state.roomId,
  + opts: { inviteSignUrl: signUrl },
  },
  });
  