Update vqvae/config.json

`LDMPipeline` use `scaling_factor` to have unit variance and which is defaults to 0.18215.
But this model config was upload before [this modification](https://github.com/huggingface/diffusers/commit/622f35b1d0dab2d76171048d988c34a911bba9d3).
Therefore, `scaling_factor` should be set to 1 to prevent the [image generation problem](https://github.com/huggingface/diffusers/issues/6725).

vqvae/config.json

@@ -22,5 +22,6 @@
     "UpDecoderBlock2D",
     "UpDecoderBlock2D",
     "UpDecoderBlock2D"
-  ]
+  ],
+  "scaling_factor": 1.0
 }