Check aodh.cache.members is defined or not

Change-Id: I3a9109e4d630593bef1ac2683ea2460f0ce428bc
diff --git a/aodh/files/newton/aodh.conf.Debian b/aodh/files/newton/aodh.conf.Debian
index 0626c3a..c82c19d 100644
--- a/aodh/files/newton/aodh.conf.Debian
+++ b/aodh/files/newton/aodh.conf.Debian
@@ -667,7 +667,7 @@
 auth_url = http://{{ server.identity.host }}:35357
 interface = {{ server.identity.get('endpoint_type', 'internal') }}
 
-{%- if server.cache is defined %}
+{%- if server.get('cache', {}).members is defined %}
 memcached_servers = {%- for member in server.cache.members %}{{ member.host }}:{{ member.get('port', '11211') }}{% if not loop.last %},{% endif %}{%- endfor %}
 {%- else %}
 token_cache_time = -1
diff --git a/aodh/files/ocata/aodh.conf.Debian b/aodh/files/ocata/aodh.conf.Debian
index 0626c3a..c82c19d 100644
--- a/aodh/files/ocata/aodh.conf.Debian
+++ b/aodh/files/ocata/aodh.conf.Debian
@@ -667,7 +667,7 @@
 auth_url = http://{{ server.identity.host }}:35357
 interface = {{ server.identity.get('endpoint_type', 'internal') }}
 
-{%- if server.cache is defined %}
+{%- if server.get('cache', {}).members is defined %}
 memcached_servers = {%- for member in server.cache.members %}{{ member.host }}:{{ member.get('port', '11211') }}{% if not loop.last %},{% endif %}{%- endfor %}
 {%- else %}
 token_cache_time = -1
diff --git a/aodh/files/pike/aodh.conf.Debian b/aodh/files/pike/aodh.conf.Debian
index e0b3ccd..dc1e62e 100644
--- a/aodh/files/pike/aodh.conf.Debian
+++ b/aodh/files/pike/aodh.conf.Debian
@@ -679,7 +679,7 @@
 cafile={{ server.identity.get('cacert_file', server.cacert_file) }}
 {%- endif %}
 
-{%- if server.cache is defined %}
+{%- if server.get('cache', {}).members is defined %}
 memcached_servers = {%- for member in server.cache.members %}{{ member.host }}:{{ member.get('port', '11211') }}{% if not loop.last %},{% endif %}{%- endfor %}
   {%- if server.cache.get('security', {}).get('enabled', False) %}
 memcache_security_strategy = {{ server.cache.security.get('strategy', 'ENCRYPT') }}