disable gtag in local env

layouts/partials/head.html

@@ -6,6 +6,7 @@
 {{- else -}}
 <meta name="ROBOTS" content="NOINDEX, NOFOLLOW">
 {{- end -}}
+{{- if ne hugo.Environment "local" -}}
 <!-- Global site tag (gtag.js) - Google Analytics -->
 <script async src="https://www.googletagmanager.com/gtag/js?id=UA-36037335-10"></script>
 <script>
@@ -15,6 +16,7 @@
 
   gtag('config', 'UA-36037335-10');
 </script>
+{{- end -}}
 
 <!-- alternative translations -->
 {{ range .Translations -}}