Remove dead code

Author: n-rodriguez

lib/ajax-datatables-rails/base.rb

@@ -4,22 +4,8 @@ module AjaxDatatablesRails
   class Base
 
     class << self
-      def rails_52?
-        Rails.gem_version >= Gem::Version.new('5.2') && Rails.gem_version <= Gem::Version.new('6.0')
-      end
-
-      def rails_60?
-        Rails.gem_version >= Gem::Version.new('6.0') && Rails.gem_version <= Gem::Version.new('6.1')
-      end
-
       def default_db_adapter
-        if rails_52?
-          ::ActiveRecord::Base.configurations.dig(Rails.env, 'adapter').downcase.to_sym
-        elsif rails_60?
-          ::ActiveRecord::Base.configurations.configs_for(env_name: Rails.env).first.config['adapter'].downcase.to_sym
-        else
-          ::ActiveRecord::Base.configurations.configs_for(env_name: Rails.env).first.adapter.downcase.to_sym
-        end
+        ::ActiveRecord::Base.configurations.configs_for(env_name: Rails.env).first.adapter.downcase.to_sym
       end
     end