Remove unused test function
Remove unused test function

The appconfig function in keystone.tests.TestCase wasn't used.
This change removes it.

Change-Id: I5377b7a3a42df1d111736f9cce0e2f74fa5931e2

UTSA-ICS/keystone-kerberos,dstanek/keystone,nuxeh/keystone,reeshupatel/demo,JioCloud/keystone,rajalokan/keystone,rodrigods/keystone,derekchiang/keystone,dsiddharth/access-keys,openstack/keystone,reeshupatel/demo,takeshineshiro/keystone,derekchiang/keystone,roopali8/keystone,rushiagr/keystone,jonnary/keystone,rodrigods/keystone,jonnary/keystone,cernops/keystone,idjaw/keystone,ilay09/keystone,himanshu-setia/keystone,rajalokan/keystone,UTSA-ICS/keystone-kerberos,nuxeh/keystone,openstack/keystone,dims/keystone,vivekdhayaal/keystone,jamielennox/keystone,dsiddharth/access-keys,klmitch/keystone,rushiagr/keystone,blueboxgroup/keystone,vivekdhayaal/keystone,maestro-hybrid-cloud/keystone,mahak/keystone,cernops/keystone,jumpstarter-io/keystone,roopali8/keystone,MaheshIBM/keystone,klmitch/keystone,reeshupatel/demo,openstack/keystone,ilay09/keystone,himanshu-setia/keystone,blueboxgroup/keystone,vivekdhayaal/keystone,dims/keystone,promptworks/keystone,ging/keystone,idjaw/keystone,ilay09/keystone,derekchiang/keystone,nuxeh/keystone,rajalokan/keystone,dsiddharth/access-keys,promptworks/keystone,dstanek/keystone,jamielennox/keystone,ging/keystone,mahak/keystone,promptworks/keystone,JioCloud/keystone,takeshineshiro/keystone,ajayaa/keystone,jumpstarter-io/keystone,rushiagr/keystone,MaheshIBM/keystone,jumpstarter-io/keystone,ajayaa/keystone,dstanek/keystone,maestro-hybrid-cloud/keystone,mahak/keystone