slapos_cloud: Call bang under Proxy Role

This is required when a computer reboots and there is an excessive number of break casts

master/bt5/slapos_cloud/WorkflowTemplateItem/portal_workflow/instance_slap_interface_workflow/scripts/RequestedInstance_bangInstanceTree.xml

@@ -52,6 +52,14 @@
             <key> <string>_params</string> </key>
             <value> <string>state_change</string> </value>
         </item>
+        <item>
+            <key> <string>_proxy_roles</string> </key>
+            <value>
+              <tuple>
+                <string>Manager</string>
+              </tuple>
+            </value>
+        </item>
         <item>
             <key> <string>id</string> </key>
             <value> <string>RequestedInstance_bangInstanceTree</string> </value>