fix: `og:image` will be incorrect if the image uses a cross-domain URL

_includes/head.html

@@ -24,6 +24,8 @@
 
   {% if page.image %}
     {% assign img = page.image.path | default: page.image %}
+
+    {% unless img contains '://' %}
       {% assign img_path = page.img_path | append: '/' | append: img | replace: '//', '/' %}
       {% capture target %}"{{ img | absolute_url }}"{% endcapture %}
 
@@ -38,6 +40,9 @@
       {% endif %}
 
       {% assign seo_tags = seo_tags | replace: target, replacement %}
+
+    {% endunless %}
+
   {% endif %}
 
   {{ seo_tags }}