reranker fixed

backend/reranker.py

@@ -7,4 +7,4 @@ reranker = FlagReranker('BAAI/bge-reranker-large',
 def rerank(query: str, documents: [str], k: int) -> [str]:
     scores = reranker.compute_score([(query, document) for document in documents])
     sorted_docs = sorted(zip(scores, documents), key=lambda x: x[0], reverse=True)
-    return sorted_docs[:k][1]
+    return [sorted_doc[1] for sorted_doc in sorted_docs[:k]]