Blazar: Fix support for external keystone in multiregion deploy

We need to correctly set keystone auth api for all cases.
By default [1] the keystone_internal_fqdn is equal to the
kolla_internal_fqdn, but in multiregion deploy it can be overriden.

1. https://github.com/openstack/kolla-ansible/blob/3a7440b370f5c2bf6f255a6530349a3e680007b9/ansible/group_vars/all.yml#L834



Change-Id: Ib40aafaa9ca360d57e87ffdd81dbc15e603fef99
Signed-off-by: Maksim Malchuk <maksim.malchuk@gmail.com>

ansible/roles/blazar/templates/blazar.conf.j2

@@ -4,7 +4,7 @@ log_dir = /var/log/kolla/blazar
 transport_url = {{ rpc_transport_url }}
 host = {{ api_interface_address }}
 port = {{ blazar_api_port }}
-os_auth_host = {{ kolla_internal_fqdn }}
+os_auth_host = {{ keystone_internal_fqdn }}
 os_auth_port = {{ keystone_admin_port }}
 os_auth_protocol = {{ admin_protocol }}
 os_auth_version = v3