Remove indent parameter for to_nice_json

It's only available in ansible 2.2.X.

templates/client.json.j2

@@ -2,6 +2,6 @@
   "client": {
     "name": "{{ sensu_client_name }}",
     "address": "{{ ansible_default_ipv4['address'] }}",
-    "subscriptions": {{ sensu_client_subscriptions | to_nice_json(indent=6) }}
+    "subscriptions": {{ sensu_client_subscriptions | to_nice_json }}
   }
 }

templates/sensu-redis.json.j2

@@ -4,7 +4,7 @@
     "password": "{{ redis_password }}",
 {% endif %}
 {% if redis_sentinels %}
-    "sentinels": {{ redis_sentinels | to_nice_json(indent=4) }},
+    "sentinels": {{ redis_sentinels | to_nice_json }},
     "master": "{{ redis_master_name }}"
 {% else %}
     "host": "{{ redis_host }}",