Fix encoding, thanks @chenull for notice.

horizon_contrib/forms/forms.py

@@ -5,7 +5,7 @@
 from django.utils.translation import ugettext_lazy as _
 from horizon import forms, messages
 from horizon_contrib.forms.models import create_or_update_and_get
-from django.utils.encoding import smart_unicode
+from django.utils.encoding import smart_text
 
 try:
     from crispy_forms.helper import FormHelper
@@ -149,7 +149,7 @@ def handle(self, request, data):
             try:
                 messages.success(
                     request,
-                    _(smart_unicode("Model %s was successfuly saved." % saved_model)))
+                    _(smart_text("Model %s was successfuly saved." % saved_model)))
             except Exception as e:
                 raise e
                 # swallowed Exception