Multisite: avoid Fatals on sites using WPMUDEV domain mapping

[jeherve]

Changes proposed in this Pull Request:

Follow-up from #18061

Our changes in namespacing caused this issue, since we're relying on an external class here.

Jetpack product discussion

• N/A

Does this pull request change what data or activity we track or use?

• No

Testing instructions:

This requires a bit of a setup, since you'd need to be using this plugin on a Multisite instance.

Once you've set that up, you shouldn't see any Fatals on your site.

Proposed changelog entry for your changes:

• Multisite: avoid Fatals on sites using WPMUDEV domain mapping

[jetpackbot]

Scheduled Jetpack release: February 2, 2021.
Scheduled code freeze: January 25, 2021

Thank you for the great PR description!

When this PR is ready for review, please apply the [Status] Needs Review label. If you are an a11n, please have someone from your team review the code if possible. The Jetpack team will also review this PR and merge it to be included in the next Jetpack release.

Generated by 🚫 dangerJS against 6acc9c0

[jeherve]

Cherry-picked to branch-9.3 in 2fb0c15

[brian-lamb-software-engineer]

Ive ran into this issue today, but the code already had its slash in there.

Fatal error: Uncaught Error: Class 'Automattic\Jetpack\Status\Host' not found in /home2/<obfuscated>/public_html/<obfuscated>.org/public/<obfuscated>/wp-content/plugins/jetpack/class.jetpack-gutenberg.php:1112

[jeherve]

@brian-lamb-software-engineer You seem to be running into a different issue, not related to this PR.

Could you tell me more about your setup? What version of Jetpack do you use, did you experience the issue multiple times or only once when updating the plugin?