Minor tweak to the RSS template.

themes/rss.tmpl

       <author>{$config.author}</author>
       <guid isPermaLink="true">{$config.domain}/posts/{$post.slug}.{$config.pageExt}</guid>
       {foreach $tag in $post.tags}
-        <category><![CDATA[ {$tag} ]]></category>
+        <category><![CDATA[ {$tag.name |noAutoescape} ]]></category>
       {/foreach}
       <description><![CDATA[ {$post.text |noAutoescape} ]]></description>
     </item>