fix the tempest failure for external ceph

show_multiple_locations is missing for external ceph, and it will
cause tempest run failed.
it means the conditon for show_multiple_locations is
glance_backend_ceph but not enable_ceph, this patch it fix it.

Change-Id: I3c95c3b0a7e34639b376bdfd0205f3930b06e2cd
Closes-Bug: #1741022
Co-Authored-By: chenqiaomin <chen.qiaomin@99cloud.net>

ansible/roles/glance/templates/glance-api.conf.j2

@@ -11,7 +11,7 @@ workers = {{ openstack_service_workers }}
 
 registry_host = {{ kolla_internal_fqdn }}
 
-{% if enable_ceph | bool %}
+{% if glance_backend_ceph | bool %}
 show_multiple_locations = True
 {% endif %}