Inconsistent spelling of gallery picker buttons

As you can see in the attached image the spelling of the "Open" button in the gallery image picker is inconsistent.

In all other languages every caption of the 3 buttons starts with a capital letter, however the german translation of the "Open" button starts with a lowercase letter.

Link to the resource file: https://code.onehippo.org/cms-community/hippo-cms-translations/blob/hippo-community-translations-12.4.0/gallerypicker/resources/org/onehippo/addon/frontend/gallerypicker/GalleryPickerPlugin_de.properties

The value for picker.open should be Öffnen

picker.open=\u00D6ffnen