Fix watch relations for nova-compute

In case when compute is combined with controller, nova-compute
should watch nova.conf.

Change-Id: Ic2438d4d977fa45a10876fd9c3c574b8383b238a
diff --git a/nova/compute.sls b/nova/compute.sls
index 7c60447..b2d0142 100644
--- a/nova/compute.sls
+++ b/nova/compute.sls
@@ -68,8 +68,6 @@
   file.managed:
   - source: salt://nova/files/{{ compute.version }}/nova-compute.conf.{{ grains.os_family }}
   - template: jinja
-  - watch_in:
-    - service: nova_compute_services
   - require:
     - pkg: nova_compute_packages
 {%- endif %}
@@ -78,6 +76,8 @@
   service.running:
   - enable: true
   - names: {{ compute.services }}
+  - watch:
+    - file: /etc/nova/nova.conf
 
 {%- set ident = compute.identity %}