Casting string to DateTime object does not check for existence of strftime.

[pradeep.gowda@…]

Similar to #2192

patch :

Index: __init__.py
===================================================================
--- __init__.py (revision 6022)
+++ __init__.py (working copy)
@@ -534,7 +534,7 @@
 
     def get_db_prep_save(self, value):
         # Casts dates into string format for entry into database.
-        if value is not None:
+        if value is not None and hasattr(value, 'strftime'):
             value = value.strftime('%Y-%m-%d')
         return Field.get_db_prep_save(self, value)

[Karen Tracey <kmtracey@…>]

Dup of #3146, which has been fixed.