Fix og:image URL to make it absolute

Author: JoelMarcey

lib/core/Head.js

@@ -39,7 +39,11 @@ class Head extends React.Component {
         {this.props.config.ogImage && (
           <meta
             property="og:image"
-            content={this.props.config.baseUrl + this.props.config.ogImage}
+            content={
+              this.props.config.url +
+              this.props.config.baseUrl +
+              this.props.config.ogImage
+            }
           />
         )}
         {this.props.redirect && (