Do not add image size without meta to OGP (regression from #4901) (#4995)

app/views/stream_entries/_og_image.html.haml

@@ -3,15 +3,18 @@
     - if media.image?
       = opengraph 'og:image', full_asset_url(media.file.url(:original))
       = opengraph 'og:image:type', media.file_content_type
+      - unless media.file.meta.nil?
         = opengraph 'og:image:width', media.file.meta['original']['width']
         = opengraph 'og:image:height', media.file.meta['original']['height']
     - elsif media.video?
       = opengraph 'og:image', full_asset_url(media.file.url(:small))
       = opengraph 'og:image:type', 'image/png'
+      - unless media.file.meta.nil?
         = opengraph 'og:image:width', media.file.meta['small']['width']
         = opengraph 'og:image:height', media.file.meta['small']['height']
       = opengraph 'og:video', full_asset_url(media.file.url(:original))
       = opengraph 'og:video:type', media.file_content_type
+      - unless media.file.meta.nil?
         = opengraph 'og:video:width', media.file.meta['small']['width']
         = opengraph 'og:video:height', media.file.meta['small']['height']
 - else