message: fix error when missing image on blog post
diff: @@ -2,7 +2,7 @@ if post.fields
  include ./partials/category_title
  a.BlogPosts__post.Type--size-sm( href="/blog/#{post.fields.slug}" )
  - if post.fields.image.fields
  + if post.fields.image && post.fields.image.fields
  img.BlogPosts__post-image(
  srcset=srcset(post.fields.image, [250, 500, 750])
  sizes="250px"
  