Warning for annotations that could not be loaded when landing on a page with no #xwikicontent container if "Display annotations by default" is enabled

Steps to reproduce

1. Go to Administer Wiki > Content > Annotations
2. Tick “Display annotations by default” and Save
3. Create a page (e.g. http://localhost:8080/xwiki/bin/view/P1/)
4. Delete the respective page
5. Go to the deleted page (e.g. http://localhost:8080/xwiki/bin/view/P1/)

Expected results

No warnings are displayed.

Actual results

Although no annotations were added before the page was deleted, the following warning is displayed:

Annotations could not be loaded because the content is not available.

Sometimes to get the warning, a refresh or even hard refresh is needed after landing on the deleted page.

The issue was reproduced on XWiki 16.10.15 and 17.10.3 as well.