Fix: Margin missing sometimes in the PR sidebar

[cheap-glitch]

Fixes #4642

Test URLs

Steps to reproduce the bug:

1. Go to repo home & reload the page
2. Navigate to the PR tab
3. Open a PR

Screenshot

capture-1633343624.mp4

[cheap-glitch]

This selector was also affecting the sidebar in PR discussions

[fregante]

The change is reasonable, but the underlying issue probably still remains. Is the differing DOM GitHub’s fault or ours? If it's their fault then this change is 100% fine.

[fregante]

Checked: It's our fault. Try:

1. Disable RGH
2. Follow your screencast
3. Enable the extension (in Firefox everything will run immediately on the current page without refresh)
4. No bug

Then try:

0. With RGH enabled
1. Follow your screencast
2. See bug

[cheap-glitch]

The change is reasonable, but the underlying issue probably still remains.

The underlying "issue" is that the styles from clean-repo-sidebar stay loaded when navigating in ajax, so the affect a page they shouldn't (which is why the bug disappears upon refreshing the page).

[fregante]

Gotchaaaa, it's all because of the classrgh-clean-repo-sidebar.

You can just add it to this page and see the issue.

Let's fix that instead, CSS should not add to undo, it should only affect what it needs to affect and nothing more (ideally)

[fregante]

D'oh, that's exactly what you did 😂 🙌

[fregante]

Love to see many bugfixes in the upcoming release, which will happen this week.