[fix] always set langauge_aliases even if it's empty

searx/engines/__init__.py

@@ -113,7 +113,6 @@ def load_engine(engine_data):
                iso_lang not in getattr(engine, 'supported_languages'):
                 language_aliases[iso_lang] = engine_lang
 
-        if language_aliases:
         setattr(engine, 'language_aliases', language_aliases)
 
     # assign language fetching method if auxiliary method exists