Koenig - Fixed missing borders on some embeds

refs TryGhost/Ghost#9724
- removed 1px white border on embed card click overlay so that it doesn't cover borders used by certain embeds such as Instagram and Facebook posts

Author: kevinansfield

lib/koenig-editor/addon/templates/components/koenig-card-embed.hbs

@@ -19,7 +19,7 @@
         <div class="kg-card-hover">
             <div class="koenig-embed-{{payload.type}} flex justify-center relative" data-kg-embed>
                 <iframe class="bn miw-100" scrolling="no"></iframe>
-                <div class="koenig-card-click-overlay ba b--white" data-kg-overlay></div>
+                <div class="koenig-card-click-overlay ba b--transparent" data-kg-overlay></div>
             </div>
 
             {{#if (or isSelected (clean-basic-html payload.caption))}}