message: Fix inviter exploding due to member being null
diff: @@ -133,12 +133,12 @@ export default class MultiInviter {
  if (!room) throw new Error("Room not found");
  const member = room.getMember(addr);
  - if (member.membership === "join") {
  + if (member?.membership === "join") {
  throw new MatrixError({
  errcode: USER_ALREADY_JOINED,
  error: "Member already joined",
  });
  - } else if (member.membership === "invite") {
  + } else if (member?.membership === "invite") {
  throw new MatrixError({
  errcode: USER_ALREADY_INVITED,
  error: "Member already invited",
  