fix handling of multiple Content-type headers This can happen if an error happens while sending application/mercurial-0.1 content. The error page will be sent resulting (for at least lighttpd) in the following headers: Content-type: application/mercurial-0.1 Content-type: text/html which result in req.proto = 'application/mercurial-0.1, text/html' fix issue344

Content-type: text/xml; charset={encoding}

<?xml version="1.0" encoding="{encoding}"?>
<rss version="2.0">
  <channel>
    <link>{urlbase}{url}</link>
    <language>en-us</language>