Fix params replication when using the dummy checker (#602)

Fix params replication when sing the dummy checker.

Author: pcuenca

src/diffusers/pipeline_flax_utils.py

@@ -427,7 +427,7 @@ def from_pretrained(cls, pretrained_model_name_or_path: Optional[Union[str, os.P
                     # make sure we don't initialize the weights to save time
                     if name == "safety_checker":
                         loaded_sub_model = DummyChecker()
-                        loaded_params = DummyChecker()
+                        loaded_params = {}
                     elif from_pt:
                         # TODO(Suraj): Fix this in Transformers. We should be able to use `_do_init=False` here
                         loaded_sub_model = load_method(loadable_folder, from_pt=from_pt)