Remove stale GA site setting records from the DB.

db/migrate/20180127005644_remove_old_ga_site_settings.rb

@@ -0,0 +1,10 @@
+class RemoveOldGaSiteSettings < ActiveRecord::Migration[5.1]
+  def up
+    execute "DELETE FROM site_settings WHERE name = 'ga_tracking_code'"
+    execute "DELETE FROM site_settings WHERE name = 'ga_domain_name'"
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end