Fixed a typo on the cookie consent

_includes/head.html

@@ -8,7 +8,7 @@
   {%- if jekyll.environment == 'production' and site.google_analytics -%}
     {%- include google-analytics.html -%}
   {%- endif -%}
-  {%- if jekyll.environment == 'production' and jekyll-cookie-consent -%}
+  {%- if jekyll.environment == 'production' and site.jekyll-cookie-consent -%}
     {%- include jekyll-cookie-consent.html -%}
   {%- endif -%}