[BUG] double scroll bar on admin ui

[huszerlbence]

🐜 Bug Report

On the admin ui in some cases two scroll bar appears at the same time.

📦 Package / Application

admin ui

📃 Version

2021.05.17.

👉 Steps To Reproduce

1. log in to a repository through admin ui
2. see double scroll-bar on the dasboard (here it's always visible)
3. in some cases it appears on other "pages" as well (like content)

🖼 Screenshots

🌍 Your Environment (for developers)

tested on Brave (bence) & Chrome (by Mariann)