[Bugfix] Remove duplicated config keyword max batch size (#1851)

Signed-off-by: tzhouam <tzhouam@connect.ust.hk>
Signed-off-by: Zhou Taichang <tzhouam@connect.ust.hk>

docs/user_guide/examples/offline_inference/text_to_image.md

@@ -49,7 +49,7 @@ if __name__ == "__main__":
 
 !!! info
 
-    For diffusion pipelines, the stage config field `stage_args.[].runtime.max_batch_size` is 1 by default, and the input
+    For diffusion pipelines, the stage config field `stage_args.[].engine_args.max_num_seqs` is 1 by default, and the input
     list is sliced into single-item requests before feeding into the diffusion pipeline. For models that do internally support
     batched inputs, you can [modify this configuration](https://github.com/vllm-project/vllm-omni/tree/main/configuration/stage_configs.md) to let the model accept a longer batch of prompts.