Set capsule.host once it is running

If the host is not set, zun-api won't know the location of the
capsule which leads to failure to delete the capsule in multi-node
environment.

Change-Id: Ie131236bb4426e12c5b8424e8eac07677dcb820a

zun/compute/manager.py

@@ -1222,6 +1222,7 @@ class Manager(periodic_task.PeriodicTasks):
                                                    requested_volumes,
                                                    requested_networks)
 
+        capsule.host = self.host
         capsule.status = consts.RUNNING
         capsule.save(context)