fix python_api example (#10196)

### What problem does this PR solve?

Fix coding example in example

### Type of change

- [x] Documentation Update

docs/references/python_api_reference.md

@@ -85,7 +85,7 @@ completion = client.chat.completions.create(
 )
 
 if stream:
-for chunk in completion:
+    for chunk in completion:
         print(chunk)
         if reference and chunk.choices[0].finish_reason == "stop":
             print(f"Reference:\n{chunk.choices[0].delta.reference}")