Fix file name of german index

content/pages/de/index.md

 template: page_with_carousel
-save_as: index_de.html
+save_as: index.html
 author: foo
 title: Landing page
 date: 2020-02-29

pelicanconf.py

@@ -26,7 +26,7 @@ AUTHOR_FEED_RSS = None
 
 # Navbar
 MENUITEMS = [
-    ('Home', '/index_de.html'),
+    ('Home', '/index.html'),
     ('News', '/archives.html'),
     ('Foo', [
         ('Bar', '/bar.html'),