message: don't NPE on invites from Dendrite
diff: @@ -1717,8 +1717,11 @@ export default createReactClass({
  } else {
  const myUserId = this.context.credentials.userId;
  const myMember = this.state.room.getMember(myUserId);
  - const inviteEvent = myMember.events.member;
  - var inviterName = inviteEvent.sender ? inviteEvent.sender.name : inviteEvent.getSender();
  + const inviteEvent = myMember ? myMember.events.member : null;
  + let inviterName = _t("Unknown");
  + if (inviteEvent) {
  + inviterName = inviteEvent.sender ? inviteEvent.sender.name : inviteEvent.getSender();
  + }
  // We deliberately don't try to peek into invites, even if we have permission to peek
  // as they could be a spam vector.
  