Revert "Use lang_override for all "en" variants."

Provide an escape from pirate day.

This reverts commit cc3af6e8ff.

r2/r2/controllers/reddit_base.py

@@ -548,7 +548,7 @@ def set_iface_lang():
     host_lang = request.environ.get('reddit-prefer-lang')
     lang = host_lang or c.user.pref_lang
 
-    if getattr(g, "lang_override") and lang.startswith("en"):
+    if getattr(g, "lang_override") and lang == "en":
         lang = g.lang_override
 
     c.lang = lang