[mod] result_container.extend sets result['engine'] = engine_name for each result

searx/results.py

 
     def extend(self, engine_name, results):
         for result in list(results):
+            result['engine'] = engine_name
             if 'suggestion' in result:
                 self.suggestions.add(result['suggestion'])
                 results.remove(result)

searx/search.py

         search_results = search_one_request(engine, query, request_params, timeout_limit)
 
         # add results
-        for result in search_results:
-            result['engine'] = engine_name
         result_container.extend(engine_name, search_results)
 
         # update engine time when there is no exception