Do not add last_request_id

It is untested and doesn't work for a while. It also causes a failure
when the method is used by other client or by keystoneclient itself.

Change-Id: Icdd53936a107933e275acd43b5ebe94b8d04bc4b
Closes-Bug: 1637530

keystoneclient/base.py

@@ -519,8 +519,6 @@ class Resource(object):
         new = self.manager.get(self.id)
         if new:
             self._add_details(new._info)
-            self._add_details(
-                {'x_request_id': self.manager.client.last_request_id})
 
     def __eq__(self, other):
         """Define equality for resources."""