Fix argument list in NeutronClientRemoteWrapper

When trying to get a cached NeutronHttpAdapter object, use:
  self.adapters.get((host, port), None)
instead of:
  self.adapters.get((host, port), None, *args, **kwargs)
since self.adapters is a dictionary.  Pass *args and **kwargs to the
NeutronHttpAdapter constructor.

Change-Id: I0075fa9c59d43b5382606fa166bdb297e25fed2e
Closes-Bug: #1383764
(cherry picked from commit 584cd92992e6382577eeaaa77941076a23c09987)
Merge "Fix argument list in NeutronClientRemoteWrapper" into stable/juno