Remove useless download link

Signed-off-by: Richard Mansfield <richardm@catalyst.net.nz>

htdocs/artefact/file/theme/raw/image_render_self.tpl

 <div>
   <a href="{$downloadpath|escape}"><img src="{$downloadpath|escape}&maxwidth=1000&maxheight=750" alt="{$title|escape}"></a>
   <p>{$description|escape}</p>
-  <div><a href="{$downloadpath|escape}">{str tag=Download section=artefact.file}</a> | <a href="{$metadataurl|escape}">{str tag=Details section=artefact.file}</a></div>
+  <div><a href="{$metadataurl|escape}">{str tag=Details section=artefact.file}</a></div>
 </div>