Make admin form lists work a bit better with non-ascii content in non-unicode tables.

 - Legacy-Id: 3203

Author: levkowetz

django/forms/models.py

@@ -965,7 +965,7 @@ def label_from_instance(self, obj):
         generate the labels for the choices presented by this object. Subclasses
         can override this method to customize the display of the choices.
         """
-        return smart_unicode(obj)
+        return smart_unicode(obj, errors='ignore')
 
     def _get_choices(self):
         # If self._choices is set, then somebody must have manually set