try fix error

patchfile.gemspec

@@ -107,6 +107,7 @@ begin
   require 'mongoid'
   require "#{dir_pwd}/app/models/concerns/slug"
   require "#{dir_pwd}/app/models/site"
+  include Site
   site_first = Site.first
   if site_first[:display_title_in_frontend].nil?
     puts 'close display double title in frontend'