flux controlnet inpaint config bug

[yigitozgenc]

What does this PR do?

config attribute not foud error for FluxMultiControlNetModel Pipeline for multi controlnet solved with same implementation huggingface#9586 with yiyixuxu suggestion in huggingface#9534

Fixes huggingface#9534 (issue)

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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• Did you write any new necessary tests?

Who can review?

@yiyixuxu
@sayakpaul

If you know how to use git blame, that is the easiest way, otherwise, here is a rough guide of who to tag.
Please tag fewer than 3 people.

Core library:

• Schedulers: @yiyixuxu
• Pipelines and pipeline callbacks: @yiyixuxu and @asomoza
• Training examples: @sayakpaul
• Docs: @stevhliu and @sayakpaul
• JAX and MPS: @pcuenca
• Audio: @sanchit-gandhi
• General functionalities: @sayakpaul @yiyixuxu @DN6

Integrations:

• deepspeed: HF Trainer/Accelerate: @SunMarc
• PEFT: @sayakpaul @BenjaminBossan

HF projects:

• accelerate: different repo
• datasets: different repo
• transformers: different repo
• safetensors: different repo

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