use ugettext_lazy

Author: KMahoney

keyvaluestore/models.py

@@ -1,5 +1,5 @@
 from django.db import models
-from django.utils.translation import ugettext as _
+from django.utils.translation import ugettext_lazy as _
 from django.core.cache import cache
 
 from keyvaluestore.managers import KeyValueStoreManager