fix DIS normalization values

rembg/sessions/dis_general_use.py

@@ -24,7 +24,7 @@ class DisSession(BaseSession):
         """
         ort_outs = self.inner_session.run(
             None,
-            self.normalize(img, (0.485, 0.456, 0.406), (1.0, 1.0, 1.0), (1024, 1024)),
+            self.normalize(img, (0.5, 0.5, 0.5), (1.0, 1.0, 1.0), (1024, 1024)),
         )
 
         pred = ort_outs[0][:, 0, :, :]