Add Basque (Euskara) new language.

Nothing critical, but would be nice to backport this to 2.77.

release/scripts/modules/bl_i18n_utils/settings.py

@@ -88,7 +88,8 @@ LANGUAGES = (
     (38, "Uzbek (Oʻzbek)", "uz_UZ"),
     (39, "Uzbek Cyrillic (Ўзбек)", "uz_UZ@cyrillic"),
     (40, "Hindi (मानक हिन्दी)", "hi_IN"),
-    (41, "Vietnamese (tiếng Việt)", "vi_VN"),
+    (41, "Vitnamese (tiếng Việt)", "vi_VN"),
+    (42, "Basque (Euskara)", "eu_EU"),
 )
 
 # Default context, in py!