Still fails once per week, at least, https://ge.xwiki.org/scans/tests?search.relativeStartTime=P28D&search.timeZoneId=Europe%2FBucharest&tests.container=org.xwiki.realtime.wysiwyg.test.ui.AllIT$NestedRealtimeWYSIWYGEditorIT&tests.test=editWithSelf#
