Adapt gnupg_key for hugo v5.22.2+

layouts/partials/widgets/contact.html

@@ -53,7 +53,7 @@
       </li>
       {{ end }}
 
-      {{ with $.Site.Params.gnupg_key}}
+      {{ with Site.Params.gnupg_key}}
       <li>
         <i class="fa-li fa fa-key fa-2x" aria-hidden="true"></i>
         <code>gpg --recv-keys {{ . }}</code>