message: don't crash on race with room members and initial composer render
  not ideal, but for now this prevents a crash at startup
  when a user-pill is persisted in local storage
diff: @@ -284,6 +284,9 @@ class UserPillPart extends PillPart {
  }
  setAvatar(node) {
  + if (!this._member) {
  + return;
  + }
  const name = this._member.name || this._member.userId;
  const defaultAvatarUrl = Avatar.defaultAvatarUrlForString(this._member.userId);
  let avatarUrl = Avatar.avatarUrlForMember(
  