RelToSqlConverter generate sql containing Scala subqueries includes redundant parentheses

@Test void testScalarSubqueryInSelectList() {
  final String sql2 = "" +
      "select\n" +
      "        (SELECT\n" +
      "          COUNT(*)\n" +
      "        FROM\n" +
      "           \"employee\"" +
      "        WHERE\n" +
      "           v.\"product_id\" >= 2), 3\n" +
      "from \"product\" as v";
  final String expected = "SELECT (((SELECT COUNT(*)\nFROM \"foodmart\".\"employee\"\nWHERE \"product\".\"product_id\" >= 2))), 3\n" +
      "FROM \"foodmart\".\"product\"";
  sql(sql2).ok(expected);
} 

(((SELECT COUNT(*)\nFROM \"foodmart\".\"employee\"\nWHERE \"product\".\"product_id\" >= 2)))

(SELECT COUNT(*)\nFROM \"foodmart\".\"employee\"\nWHERE \"product\".\"product_id\" >= 2)