fix: the grid body is hidden after resizing the grid

[js87zz]

Please check if the PR fulfills these requirements

• It's submitted to right branch according to our branching model
• It's right issue type on title
• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)
• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes/features)
• Docs have been added/updated (for bug fixes/features)
• It does not introduce a breaking change or has description for the breaking change

Description

• fixed the grid body is hidden after resizing the grid
  

---

Thank you for your contribution to TOAST UI product. 🎉 😘 ✨

[lja1018]

리뷰완료합니다.

[adhrinae]

리뷰 완료합니다.

[dongsik-yoo]

리뷰 완료합니다. 수고하셨습니다.