DatePicker 404 Not Found for datepicker-en.js file

[almaz-free]

"DatePicker" class in "yii2-jui" call "DatePickerLanguageAsset" class for registering JavaScript "ui/i18n/datepicker-$language.js" file with language translation for "jQuery UI".
It has check if ($language !== 'en-US') but, if our locale set to 'language' => 'en', it truing include datepicker-en.js file, which not exist in directory "/ui/i18n/".
So we have error in app.log and "Failed to load resource" 404 (Not Found) in browser console.

I think, we need add check for 'en' locale too:
if ($language !== 'en-US' && $language !== 'en')