message: fix pg statement
diff: @@ -521,7 +521,7 @@ export class PgDataStore implements DataStore {
  public async getCountForUsernamePrefix(domain: string, usernamePrefix: string): Promise<number> {
  const res = await this.pgPool.query("SELECT COUNT(*) FROM client_config " +
  - "WHERE config->>'username' LIKE $1; AND domain = $2",
  + "WHERE domain = $2 AND config->>'username' LIKE $1 ",
  [`${usernamePrefix}%`, domain]);
  return res.rows[0];
  }
  