message: Null-guard member mention pills for rooms you have left (notif panel)
diff: @@ -127,7 +127,7 @@ const Pill = createReactClass({
  }
  break;
  case Pill.TYPE_USER_MENTION: {
  - const localMember = nextProps.room.getMember(resourceId);
  + const localMember = nextProps.room ? nextProps.room.getMember(resourceId) : undefined;
  member = localMember;
  if (!localMember) {
  member = new RoomMember(null, resourceId);
  