Redundant unique constraint
Redundant unique constraint

federation extension have redundant unique constraint. The unique
constraint is totally useless, as (id, idp_id) columns are
columns of a composite primary key, which is unique by definition.

Change-Id: I93648ab89b26d7e77875a1faa8575a146224232f
Partial-Bug: #1292591

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