Very minor (but important to fix) typo

In comment.tpl.php it says this: <div clas="content"><?php print $content; ?></div>
but it should say this: <div class</b>="content"><?php print $content; ?></div>

I'd submit a patched but I don't think it's worth it for that single missing 's'. Still, if people are having problems using CSS to change the content div in their comments, this is why.