Fix InsertWhitelist test in composite primary key table

[benevolent0505]

• The table has a composite primary key with columns that have default values and columns that don't.
• ColumnsWithoutDefault columns don't guarantee unique records.

What version of SQLBoiler are you using (sqlboiler --version)?

SQLBoiler v4.18.0

What is your database and version (eg. Postgresql 10)

MySQL 8.0.34

Please provide a relevant database schema so we can replicate your issue (Provided you are comfortable sharing this)

CREATE TABLE IF NOT EXISTS `dummy` (
  `id` INT NOT NULL,

  `created_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,

  PRIMARY KEY (`id`, `created_at`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;