[Upstream] Cherry-pick 2b5c07eb

https://github.com/sergiokopplin/indigo/commit/2b5c07ebfc6b577e6a1aa083ae758034682d1356

_includes/social-links.html

@@ -24,7 +24,7 @@
     {% endif %}
 
     {% if site.linkedin %}
-        <a class="link" data-title="linkedin.com/in/{{ site.linkedin }}" href="http://linkedin.com/in/{{ site.linkedin }}" target="_blank">
+        <a class="link" data-title="linkedin.com/in/{{ site.linkedin }}" href="http://www.linkedin.com/in/{{ site.linkedin }}" target="_blank">
             {% fa_svg fab.fa-linkedin %}
         </a>
     {% endif %}