flow-delete-post-content in english is:
This comment was deleted by $1 ([$2 history])
$2 seems to expect to be a URL, but instead it gets a USERNAME (talk | contribs)
See example in https://www.mediawiki.org/w/index.php?title=Topic:Sdoatsbslsafx6lw&curid=0&action=history&uselang=en