Remove obsolete identity-v3-only job

Keystone v2 was removed in Queens, so all devstack builds are now
identity-v3-only.

Change-Id: Icb01161be206576ad9445baca6b2a880fb1ef0e0

.zuul.yaml

@@ -33,7 +33,6 @@
       use_amqp1: 0
       use_apache: 1
       use_python3: 0
-      use_identity_v3_only: 0
       branch_override: default
 
 - job:
@@ -66,14 +65,6 @@
     vars:
       use_python3: 1
 
-- job:
-    name: heat-functional-convg-mysql-lbaasv2-identity-v3-only
-    parent: heat-functional-devstack-base
-    voting: false
-    branches: master
-    vars:
-      use_identity_v3_only: 1
-
 - job:
     name: grenade-heat
     parent: legacy-dsvm-base
@@ -118,7 +109,6 @@
         - heat-functional-convg-mysql-lbaasv2-amqp1
         - heat-functional-convg-mysql-lbaasv2-non-apache
         - heat-functional-convg-mysql-lbaasv2-py35
-        - heat-functional-convg-mysql-lbaasv2-identity-v3-only
         - openstack-tox-lower-constraints
     gate:
       jobs:

playbooks/devstack/functional/run.yaml

@@ -81,9 +81,6 @@
           if [ "{{ branch_override }}" != "default" ] ; then
               export OVERRIDE_ZUUL_BRANCH=$BRANCH_OVERRIDE
           fi
-          if [ "{{ use_identity_v3_only }}" -eq 1 ] ; then
-              export DEVSTACK_LOCAL_CONFIG+=$'\n'"ENABLE_IDENTITY_V2=False"
-          fi
           if [ "{{ use_apache  }}" -eq 0 ] ; then
               export DEVSTACK_LOCAL_CONFIG+=$'\n'"HEAT_USE_MOD_WSGI=False"
           fi