Change link previews for statuses to never use avatar as fallback (#23376)

app/views/statuses/_og_image.html.haml

@@ -45,7 +45,4 @@
   - else
     = opengraph 'twitter:card', 'summary_large_image'
 - else
-  = opengraph 'og:image', full_asset_url(account.avatar.url(:original))
-  = opengraph 'og:image:width', '400'
-  = opengraph 'og:image:height','400'
   = opengraph 'twitter:card', 'summary'