Fix the memcache location value in horizon local settings

When setting multi memcached servers, the value should be a list
rather then a comma joined string

This patch set I586ce1c6c3300254c4e2a398ff46645df576aeb0 set it in
wrong

TrivialFix

Change-Id: Ic612658ab0310c6764310bbca92c925da6d47f6c

ansible/roles/horizon/templates/local_settings.j2

@@ -136,7 +136,7 @@ CACHES = {
 {% if orchestration_engine == 'KUBERNETES' %}
         'LOCATION': '{{ memcached_servers }}'
 {% else %}
-        'LOCATION': '{% for host in groups['memcached'] %}{{ hostvars[host]['ansible_' + hostvars[host]['api_interface']]['ipv4']['address'] }}:{{ memcached_port }}{% if not loop.last %},{% endif %}{% endfor %}'
+        'LOCATION': [{% for host in groups['memcached'] %}'{{ hostvars[host]['ansible_' + hostvars[host]['api_interface']]['ipv4']['address'] }}:{{ memcached_port }}'{% if not loop.last %},{% endif %}{% endfor %}]
 {%- endif %}
     }
 }