message: linting tweak
diff: @@ -518,7 +518,7 @@ export class PgDataStore implements DataStore {
  [username, domain]
  );
  if (res.rowCount === 0) {
  - return;
  + return undefined;
  }
  else if (res.rowCount > 1) {
  log.error("getMatrixUserByUsername returned %s results for %s on %s", res.rowCount, username, domain);
  @@ -546,7 +546,7 @@ export class PgDataStore implements DataStore {
  await this.pgPool.query(statement, [userId, Date.now()]);
  }
  - public async getLastSeenTimeForUsers(): Promise<{ user_id: string, ts: number }[]> {
  + public async getLastSeenTimeForUsers(): Promise<{ user_id: string; ts: number }[]> {
  const res = await this.pgPool.query(`SELECT * FROM last_seen`);
  return res.rows;
  }
  