fixed openai_functions api_response format args err

root cause: args may not have a key (params) resulting in an error

libs/langchain/langchain/chains/openai_functions/openapi.py

@@ -227,7 +227,7 @@ class SimpleRequestChain(Chain):
             response = (
                 f"{api_response.status_code}: {api_response.reason}"
                 + f"\nFor {name} "
-                + f"Called with args: {args['params']}"
+                + f"Called with args: {args.get('params','')}"
             )
         else:
             try: