Set calendar feed language correctly

aleksis/core/mixins.py

@@ -668,7 +668,7 @@ class CalendarEventMixin(RegistryObject):
     @classmethod
     def get_language(cls, request) -> str:
         """Return the language of the calendar feed."""
-        return "en"  # FIXME
+        return request.LANGUAGE_CODE
 
     @classmethod
     def get_color(cls, request) -> str: