FIX: remove gtm_ua_domain_name setting because it's preferable to configure it in Google Tag Manager settings

app/helpers/application_helper.rb

@@ -15,9 +15,11 @@ module ApplicationHelper
   include ConfigurableUrls
   include GlobalPath
 
-  def google_universal_analytics_json(ua_domain_name)
-    cookie_domain = ua_domain_name.gsub(/^http(s)?:\/\//, '')
-    result = {cookieDomain: cookie_domain}
+  def google_universal_analytics_json(ua_domain_name=nil)
+    result = {}
+    if ua_domain_name
+      result[:cookieDomain] = ua_domain_name.gsub(/^http(s)?:\/\//, '')
+    end
     if current_user.present?
       result[:userId] = current_user.id
     end
@@ -29,7 +31,7 @@ module ApplicationHelper
   end
 
   def google_tag_manager_json
-    google_universal_analytics_json(SiteSetting.gtm_ua_domain_name)
+    google_universal_analytics_json
   end
 
   def shared_session_key

config/locales/server.en.yml

@@ -915,7 +915,6 @@ en:
     ga_universal_tracking_code: "Google Universal Analytics (analytics.js) tracking code code, eg: UA-12345678-9; see http://google.com/analytics"
     ga_universal_domain_name: "Google Universal Analytics (analytics.js) domain name, eg: mysite.com; see http://google.com/analytics"
     gtm_container_id: "Google Tag Manager container id. eg: GTM-ABCDEF"
-    gtm_ua_domain_name: "Universal Analytics via Google Tag manager domain name. 'auto' is recommended."
     enable_escaped_fragments: "Fall back to Google's Ajax-Crawling API if no webcrawler is detected. See https://developers.google.com/webmasters/ajax-crawling/docs/learn-more"
     enable_noscript_support: "Enable standard webcrawler search engine support via the noscript tag"
     allow_moderators_to_create_categories: "Allow moderators to create new categories"

config/site_settings.yml

@@ -101,9 +101,6 @@ basic:
     client: true
     default: ''
     regex: "^GTM-"
-  gtm_ua_domain_name:
-    client: true
-    default: 'auto'
   top_menu:
     client: true
     refresh: true