i18n: make sure 'en' in Accept-Language is recognized as having 100% coverage The workaround in 7c7d6b5c07c7 no longer works after upstream addressed the main issue and released the changes in TurboGears 2.4.3 . Setting `i18n.native = en` in the .ini works as a workaround. The native language for translations is an implementation detail that users shouldn't have to configure, so we define it as a default value without making it explicit in the generated .ini template files. Note that even though TG will figure out that languages like `en_US` should fall back to using the `en` `kallithea.mo`, it doesn't consider `en_US` native if `en` is in the native list but `en_US` isn't. We thus include the most common aliases for `en` in the list.