[e] (0) Remove a note about a possible canvas change, since it hasn't happened for a few years now.
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=26834
Affected topics: Canvas, HTML

git-svn-id: https://svn.whatwg.org/webapps@8813 340c8d12-0b0e-0410-8428-c7bf67bfef74