It is written in "English, United States".
Translations can be done manually by going to the properties and give an entry in the properties.
Another option for translations batch translate (Edit Batch translate) and select "English, United States" and your project language.
When "English, United States" is not listed go to Project -> Settings and add "EnUS" to the languages. After you have translated everything to your project language you can remove the "EnUS" again.