fix xlabs FLUX lora conversion typo

[Clement-Lelievre]

What does this PR do?

Typo fixing for XLab FLUX LoRA conversion to diffusers.
In its current version, this raises: TypeError: slice indices must be integers or None or have an __index__ method because str.startswith expects a tuple of strs or a single str.
(Unless I've missed an issue on this topic, I'm a bit surprised this typo has been here for over a month without anyone complaining)

Repro steps:

1. instanciate a flux pipeline
2. get a xlab lora safetensors
3. run pipe.load_lora_weights(xlab_lora) , passing the lora from step 2

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?

@sayakpaul , @yiyixuxu

[sayakpaul]

Thank you for this. The reason why, it was not brought up because we don't test for an Xlabs LoRA that has single_block components:

diffusers/tests/lora/test_lora_layers_flux.py

Line 252 in 99f6082

self.pipeline.load_lora_weights("XLabs-AI/flux-lora-collection", weight_name="disney_lora.safetensors")

[HuggingFaceDocBuilderDev]

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[Clement-Lelievre]

@sayakpaul from a cursory glance from my phone it seems the failed test is unrelated to the diff of this PR

[sayakpaul]

@Clement-Lelievre possible to push an empty commit?

[Clement-Lelievre]

@Clement-Lelievre possible to push an empty commit?

done

[sayakpaul]

Failing test is completely unrelated.

[sayakpaul]

Thank you for the PR!

[Clement-Lelievre]

@sayakpaul as follow-up, using the same xlabs lora the conversion now works, however I now get the error: Adapter name(s) {'<my_adapter_name>'} not in the list of present adapters: set(). raised here since this PR

Possibly because get_list_adapters fails to add a component?

[sayakpaul]

Can you open a new issue with a reproducible snippet?