fix when 0 results

app.py

@@ -24,7 +24,7 @@ def fake_search(question, retriever_top_k, reader_top_k):
 def search(question, retriever_top_k, reader_top_k):
   query_result = extractive_query.search_by_query(query = question, retriever_top_k = retriever_top_k, reader_top_k = reader_top_k, es_index = "informecomisionverdad")
   result = []
-  for i in range(0, reader_top_k):
+  for i in range(0, len(query_result)):
     item = query_result[i]
     result.append([[i+1], item.answer, item.context[:200], item.meta['title'], item.meta['source']])