fix backward compatibility for case loading preconverted sd without saved safety checker (#1004)

Author: eaidova

optimum/intel/openvino/modeling_diffusion.py

@@ -429,6 +429,14 @@ def _from_pretrained(
                 # Check if the module is in a subdirectory
                 if (model_save_path / name).is_dir():
                     submodels[name] = load_method(model_save_path / name)
+                # For backward compatibility with models exported using previous optimum version, where safety_checker saving was disabled
+                elif name == "safety_checker":
+                    logger.warning(
+                        "Pipeline config contains `safety_checker` subcomponent, while `safety_checker` is not available in model directory. "
+                        "`safety_checker` will be disabled. If you want to enable it please set it explicitly to `from_pretrained` method "
+                        "or reexport model with new optimum-intel version"
+                    )
+                    submodels[name] = None
                 else:
                     submodels[name] = load_method(model_save_path)