bug 878431: Minor changes to auth_token middleware.
bug 878431: Minor changes to auth_token middleware.

Change-Id: I3aa28db2dcd0be0f19f7e25ac1741e34fb145220

ilay09/keystone,savi-dev/keystone,kwss/keystone,takeshineshiro/keystone,dsiddharth/access-keys,rodrigods/keystone,sileht/deb-openstack-keystone,ntt-sic/keystone,townbull/keystone-dtrust,jamielennox/keystone,ging/keystone,cernops/keystone,sileht/deb-openstack-keystone,cbrucks/keystone_ldap,ajayaa/keystone,jumpstarter-io/keystone,rushiagr/keystone,ilay09/keystone,nuxeh/keystone,townbull/keystone-dtrust,admiyo/keystone,maestro-hybrid-cloud/keystone,cbrucks/keystone_ldap,jonnary/keystone,MaheshIBM/keystone,mahak/keystone,cbrucks/Federated_Keystone,himanshu-setia/keystone,UTSA-ICS/keystone-kerberos,jumpstarter-io/keystone,openstack/keystone,rickerc/keystone_audit,dsiddharth/access-keys,rajalokan/keystone,cbrucks/keystone_ldap,rickerc/keystone_audit,nuxeh/keystone,openstack/keystone,rickerc/keystone_audit,ntt-sic/keystone,cloudbau/keystone,admiyo/keystone,jumpstarter-io/keystone,klmitch/keystone,takeshineshiro/keystone,cbrucks/Federated_Keystone,jamielennox/keystone,derekchiang/keystone,dstanek/keystone,idjaw/keystone,kwss/keystone,townbull/keystone-dtrust,dims/keystone,vivekdhayaal/keystone,dstanek/keystone,himanshu-setia/keystone,rushiagr/keystone,dstanek/keystone,klmitch/keystone,cernops/keystone,rajalokan/keystone,MaheshIBM/keystone,rajalokan/keystone,ilay09/keystone,promptworks/keystone,ntt-sic/keystone,mahak/keystone,dsiddharth/access-keys,idjaw/keystone,vivekdhayaal/keystone,citrix-openstack-build/keystone,nuxeh/keystone,cloudbau/keystone,promptworks/keystone,reeshupatel/demo,sileht/deb-openstack-keystone,blueboxgroup/keystone,mahak/keystone,ajayaa/keystone,citrix-openstack-build/keystone,roopali8/keystone,cbrucks/Federated_Keystone,dims/keystone,rushiagr/keystone,JioCloud/keystone,promptworks/keystone,cloudbau/keystone,JioCloud/keystone,derekchiang/keystone,roopali8/keystone,reeshupatel/demo,blueboxgroup/keystone,UTSA-ICS/keystone-kerberos,ging/keystone,jonnary/keystone,reeshupatel/demo,rodrigods/keystone,maestro-hybrid-cloud/keystone,admiyo/keystone,vivekdhayaal/keystone,kwss/keystone,derekchiang/keystone,savi-dev/keystone,openstack/keystone,citrix-openstack-build/keystone,savi-dev/keystone