Revert a localizable string change

[crazytonyli]

Introduced in #25454, and caused trouble in the release process:

Inconsistencies found between 'en' and 'zh-Hant':
addSite.selfHosted.loadingSiteInfoFailure expected placeholders for [String] but found [] instead.

[dangermattic]

	1 Warning
⚠️	This PR is assigned to the milestone 26.8 ❄️. The due date for this milestone has already passed. Please assign it to a milestone with a later deadline or check whether the release for this milestone has already been finished.

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress by scanning the QR code below to install the corresponding build.

	App Name	WordPress
	Configuration	Release-Alpha
	Build Number	31806
	Version	PR #25460
	Bundle ID	org.wordpress.alpha
	Commit	1f6e064
	Installation URL	3iaeekr0rbmqo

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[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack by scanning the QR code below to install the corresponding build.

	App Name	Jetpack
	Configuration	Release-Alpha
	Build Number	31806
	Version	PR #25460
	Bundle ID	com.jetpack.alpha
	Commit	1f6e064
	Installation URL	5vr6snp000968

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[crazytonyli]

I'll merge this PR to unblock releasing a new beta.