FIX: if an enum is Fixnum do not allow strings to live in it

lib/site_setting_extension.rb

@@ -291,6 +291,7 @@ module SiteSettingExtension
     end
 
     if type == types[:enum]
+      val = val.to_i if Fixnum === defaults[name.to_sym]
       if enum_class(name)
         raise Discourse::InvalidParameters.new(:value) unless enum_class(name).valid_value?(val)
       else