fix: kwargs in custom Sentence Transformer

custom_st.py

@@ -98,7 +98,7 @@ class Transformer(nn.Module):
             'revision': model_kwargs.get('revision', None),
             'local_files_only': model_kwargs.get('local_files_only', None),
         }
-        image_processor_kwargs.update(image_processor_args)
+        image_processor_kwargs.update(image_processor_args or {})
 
         config = AutoConfig.from_pretrained(
             model_name_or_path, cache_dir=cache_dir, **config_kwargs