Spurious warning "Annotation could not be loaded" on the history page, if annotations are enabled

Steps to reproduce:

• in the wiki admin, section "Annotations" set the options "Annotations are activated", "Display annotations by default " and "Display annotations highlight by default " to "yes"
• go to any page and click on the "history" to see the "history" tab
• click on the "Show minor edits" button to get to the view with "viewer=history"

After the plage loads one can see a warning in orange appear at the bottom:
"Annotations could not be loaded because the content is not available."
This message does no harm and vanishes after a moment, but it might irritate some users