Updated openstack/openstack
Project: openstack/keystonemiddleware  007dbb2b9ebadbc0278437558db3fe28ce8300df

remove unused variable in _IdentityServer

Remove the unused variable AUTH_VERSION in _IdentityServer. I think
this is the variable that we forgot wo delete when we refacotr code.

Change-Id: I5e45cf28f4f8157539aba8e17fdb345f5dca08f1