fix(v2): restore toggle responsive sidebar button

[lex111]

Motivation

Fix small bug caused by merge #4617.

Have you read the Contributing Guidelines on pull requests?

Yes

Test Plan

Try to close responsive sidebar.

Related PRs

(If this PR adds or changes functionality, please take some time to update the docs at https://github.com/facebook/docusaurus, and link to your PR here.)

[github-actions]

Size Change: 0 B

Total Size: 599 kB

ℹ️ View Unchanged

Filename	Size	Change
website/build/assets/css/styles.********.css	87.2 kB	0 B
website/build/assets/js/main.********.js	422 kB	0 B
website/build/blog/2017/12/14/introducing-docusaurus/index.html	62.1 kB	0 B
website/build/docs/introduction/index.html	235 B	0 B
website/build/index.html	26.9 kB	0 B

_{compressed-size-action}

[netlify]

[V2]

Built with commit a85c498

https://deploy-preview-4620--docusaurus-2.netlify.app

[netlify]

[V1]

Built with commit a85c498

https://deploy-preview-4620--docusaurus-1.netlify.app

[lex111]

@slorber please re-run production build: https://app.netlify.com/sites/docusaurus-2/deploys/6078b51ffddd450007bb4c3d

1:35:33 AM: ❌ Fetching project info
1:35:33 AM: ❌ Failed to collect project info. Please contact our support team for help
1:35:33 AM: ❌ Error from server: <Code: 409, Message: Another build is currently in progress. Please wait until it's finished.>
1:35:33 AM: ╭──────────────────────────────────────────────────────────────────────────────╮
1:35:33 AM: │           New version of Crowdin CLI is available! 3.5.3 -> 3.5.5            │
1:35:33 AM: ├──────────────────────────────────────────────────────────────────────────────┤
1:35:33 AM: │      Changelog: https://github.com/crowdin/crowdin-cli/releases/latest       │
1:35:33 AM: │                      Please update for best experience!                      │
1:35:33 AM: ╰──────────────────────────────────────────────────────────────────────────────╯
1:35:33 AM: error Command failed with exit code 1.
1:35:33 AM: info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
1:35:33 AM: error Command failed with exit code 1.
1:35:33 AM: info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
1:35:33 AM: error Command failed with exit code 1.
1:35:33 AM: info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
1:35:33 AM: error Command failed.
1:35:33 AM: Exit code: 1

[slorber]

oh thanks, missed that!

[slorber]

Minor optim fix: #4626