[placement] Fix misleading comment in wsgi loader

Placement API is not a paste app so we shouldn't suggest that it is.

Change-Id: I6150160ac3d810ad4eaa3217d41eade64aa30069

nova/api/openstack/placement/wsgi.py

@@ -61,5 +61,5 @@ def init_application():
             logging.getLogger(__name__),
             logging.DEBUG)
 
-    # build our paste app and return it for wsgi goodness
+    # build and return our WSGI app
     return deploy.loadapp(conf.CONF)