[Error-Handling] Server DB Connection Error

> ### 어떤 에러인가요?
> * server npm start 시 DB Connection Error
> ### 에러 메시지
>
```shell
Error: connect ECONNREFUSED ::1:3306
at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1195:16)
--------------------
at Protocol._enqueue (/Users/user/Desktop/coding/codestates/Roadgram/server/node_modules/mysql/lib/protocol/Protocol.js:144:48)
at Protocol.handshake (/Users/user/Desktop/coding/codestates/Roadgram/server/node_modules/mysql/lib/protocol/Protocol.js:51:23)
at PoolConnection.connect (/Users/user/Desktop/coding/codestates/Roadgram/server/node_modules/mysql/lib/Connection.js:116:18)
at Pool.getConnection (/Users/user/Desktop/coding/codestates/Roadgram/server/node_modules/mysql/lib/Pool.js:48:16)
at /Users/user/Desktop/coding/codestates/Roadgram/server/src/driver/mysql/MysqlDriver.ts:981:18
```

> ### 에러 핸들링 방법
> * 핸들링 방법에 대해서 간단하게 기록해보세요.
> TypeORM config 파일에서 host를 localhost -> 127.0.0.1로 변경
> ### 에러 핸들링을 위해 참고한 레퍼런스 링크
> [링크] https://github.com/vercel/next.js/discussions/36070