initialize the hasher for unscoped token

Using PKI tokens results in an empty
projects list in horizon and a 403 error from
keystone.

Change-Id: If6853343125112340e447e760ee7d997e6e7384f
Closes-Bug: #1484499
Closes-Bug: #1486745
(cherry picked from commit aed28851b9)

openstack_auth/user.py

@@ -89,6 +89,7 @@ class Token(object):
             hasher.update(self.id)
             self.id = hasher.hexdigest()
             # If the scoped_token is long, then unscoped_token must be too.
+            hasher = hashlib.new(algorithm)
             hasher.update(self.unscoped_token)
             self.unscoped_token = hasher.hexdigest()
         self.expires = auth_ref.expires