fix: fixed the issue of error reporting when saving chat configuration #965 (#984)

### What problem does this PR solve?

fix: fixed the issue of error reporting when saving chat configuration
#965

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/pages/chat/chat-configuration-modal/index.tsx

@@ -145,7 +145,8 @@ const ChatConfigurationModal = ({
           settledModelVariableMap[ModelVariableType.Precise],
         icon: fileList,
         llm_id: initialDialog.llm_id ?? modelId,
-        vector_similarity_weight: 1 - initialDialog.vector_similarity_weight,
+        vector_similarity_weight:
+          1 - (initialDialog.vector_similarity_weight ?? 0.3),
       });
     }
   }, [initialDialog, form, visible, modelId]);