Use six.text_type() to convert exceptions
Use six.text_type() to convert exceptions

They might contains Unicode data.

Change-Id: I6edb079197cac6f7575572c25c37a5be14b3c1d9

leandroreox/gnocchi,sileht/gnocchi,idegtiarov/gnocchi-rep,idegtiarov/gnocchi-rep,gnocchixyz/gnocchi,gnocchixyz/gnocchi,idegtiarov/gnocchi-rep,sileht/gnocchi,leandroreox/gnocchi