Infinite same ALTERs upon startup (mysql, ver 0.2.30)

[Overtorment]

Issue Description

Upon every startup, typeorm does the same alter. Over and over again. Same alter upon each startup:

ALTER TABLE `push_log` CHANGE `created` `created` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP

Expected Behavior

No alters upon startup when its not necessary

Actual Behavior

Upon every startup, typeorm does the same alter. Over and over again. Same alter upon each startup.
removing @Index(["created"], { unique: false }) helped.
I could reproduce it both on heroku and my laptop ubuntu linux.
I don't know if it was introduced in typeorm only recently, or it was always there and I only noticed because production table grew big
and alter started taking minutes and I actually noticed it.

Steps to Reproduce

In previous to this fix commit It was reproduceable: BlueWallet/GroundControl@7b3b6f3

table that we have:

CREATE TABLE `push_log` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `token` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
  `success` tinyint(4) NOT NULL,
  `created` timestamp NOT NULL DEFAULT current_timestamp(),
  `os` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
  `response` text COLLATE utf8mb4_unicode_ci NOT NULL,
  `payload` text COLLATE utf8mb4_unicode_ci NOT NULL,
  PRIMARY KEY (`id`),
  KEY `IDX_6df7a76e08bef8f18159126734` (`token`),
  KEY `IDX_477ed76495567d90c759b416b4` (`created`)
) ENGINE=InnoDB AUTO_INCREMENT=1362892 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci

entity definition:

import { Entity, PrimaryGeneratedColumn, Column, Index } from "typeorm";

@Entity()
@Index(["token"], { unique: false })
@Index(["created"], { unique: false })
export class PushLog {
  @PrimaryGeneratedColumn()
  id: number;

  @Column()
  token: string;

  @Column()
  os: string;

  @Column("text")
  payload: string;

  @Column("text")
  response: string;

  @Column()
  success: boolean;

  @Column({ type: "timestamp", default: () => "CURRENT_TIMESTAMP" })
  created: Date;
}

My Environment

Dependency	Version
Operating System	heroku. linux..?
Node.js version	v14.15.3
Typescript version	4.1.3
TypeORM version	0.2.30

Relevant Database Driver(s)

• aurora-data-api
• aurora-data-api-pg
• better-sqlite3
• cockroachdb
• cordova
• expo
• mongodb
• mysql
• nativescript
• oracle
• postgres
• react-native
• sap
• sqlite
• sqlite-abstract
• sqljs
• sqlserver