Use glance::<service>::authtoken to configure keystone_authtoken
section in glance configs, with all parameters required
to configure keystonemiddleware.
Also changed auth_type to auth_strategy, because auth_type is
related to keystone authentication.
Change-Id: I722a1e41b2cee0b3040c37f07adfd13c33edaa5c
Closes-bug: #1604463