Remove nosetests i18n fix

As cinder doesn't use python-nose library for testing more,
we can get rid of this.

Change-Id: I393d31398d1e7455bfbef394fdd3a095436c5d01

cinder/tests/unit/__init__.py

@@ -23,16 +23,11 @@
 """
 
 import eventlet
-from six.moves import builtins
 
 from cinder import objects
 
 eventlet.monkey_patch()
 
-# See http://code.google.com/p/python-nose/issues/detail?id=373
-# The code below enables nosetests to work with i18n _() blocks
-setattr(builtins, '_', lambda x: x)
-
 # NOTE(alaski): Make sure this is done after eventlet monkey patching otherwise
 # the threading.local() store used in oslo_messaging will be initialized to
 # threadlocal storage rather than greenthread local.  This will cause context