Handle "unknown" media

On mastodon.social, images have type:image, but hachyderm returns type:unknown

Found this when editing a post and add two images, on mastodon.social.

src/components/status.jsx

@@ -54,7 +54,8 @@ function Media({ media, showOriginal, onClick }) {
     focalBackgroundPosition = `${x.toFixed(0)}% ${y.toFixed(0)}%`;
   }
 
-  if (type === 'image') {
+  if (type === 'image' || (type === 'unknown' && previewUrl && url)) {
+    // Note: type: unknown might not have width/height
     return (
       <div
         class={`media media-image`}