Handled missing html property for NFT Oembed response

refs https://github.com/TryGhost/Team/issues/1211

Since we have switched to rendering the NFT card outside of the OEmbed
response we no longer include a html property. This check would throw
for missing HTML so we've updated it to not include NFT cards

ghost/admin/lib/koenig-editor/addon/components/koenig-card-embed.js

@@ -177,7 +177,7 @@ export default Component.extend({
                 this.send('insertAsBookmark', response);
                 return;
             }
-            if (!response.html) {
+            if (!response.html && response.card_type !== 'nft') {
                 throw 'No HTML returned';
             }