Fixed #25389 -- Fixed pickling a SimpleLazyObject wrapping a model.

Pickling a `SimpleLazyObject` wrapping a model did not work correctly; in
particular it did not add the `_django_version` attribute added in 42736ac8.
Now it will handle this and other custom `__reduce__` methods correctly.

tests/utils_tests/models.py

@@ -11,3 +11,7 @@ class Category(models.Model):
 class Thing(models.Model):
     name = models.CharField(max_length=100)
     category = models.ForeignKey(Category, models.CASCADE)
+
+
+class CategoryInfo(models.Model):
+    category = models.OneToOneField(Category, models.CASCADE)