Make sure user dict has id key before checking against it
Make sure user dict has id key before checking against it

The user dict passed to the update_user() method doesn't
always have a key called 'id'. Make sure we check for
the existence of the key before getting its value.

Change-Id: I760fb6d99aa517a6877d8fb0124da78b0ec5f4b7
Fixes: LP #1022411

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