[tls] Make a cert SLS IDs globally unique

At the moment most of openstack formulas have
the same ids of certs at state files, e.g.:

 nova/server.sls   - rabbitmq_ca : file_managed
 glance/server.sls - rabbitmq_ca : file_managed

So, any attempt to use the:

   salt-call state.apply

fails with:

  Detected conflicting IDs, SLS IDs need to be
  globally unique.

Change-Id: I2bb1baca6709282a6bfc075a7497ea9c447da7e5
diff --git a/heat/server.sls b/heat/server.sls
index f0ab5ac..2868af6 100644
--- a/heat/server.sls
+++ b/heat/server.sls
@@ -130,14 +130,14 @@
     - file: /etc/heat/heat.conf
     - file: /etc/heat/api-paste.ini
     {%- if server.message_queue.get('ssl',{}).get('enabled', False) %}
-    - file: rabbitmq_ca
+    - file: rabbitmq_ca_heat_server
     {%- endif %}
     {%- if server.database.get('ssl',{}).get('enabled', False) %}
     - file: mysql_ca_heat_server
     {%- endif %}
 
 {%- if server.message_queue.get('ssl',{}).get('enabled', False) %}
-rabbitmq_ca:
+rabbitmq_ca_heat_server:
 {%- if server.message_queue.ssl.cacert is defined %}
   file.managed:
     - name: {{ server.message_queue.ssl.cacert_file }}