Add `scale_factor` to vae config.

Hey julien-c 👋,

Your model repository seems to contain a stable diffusion checkpoint. We have just merged a [PR](https://github.com/huggingface/diffusers/pull/1860) in `diffusers` which makes `scaling_factor` (the magic 0.18215 number a config attribute of `vae`).

We strongly recommend that you merge this PR to make sure your model keeps working correctly with diffusers.

Diffusingly,
Suraj.

vae/config.json

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
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-size 706
+oid sha256:0df5153a82659a3f04d2f90d9df5a229d4d47b21d466153aa89f95abe64385a4
+size 735