Fix merge error in central/manager.py

We should not be using nova's manager.

Change-Id: I36af1b1aaa11a41545fa8f67a3c084cc3150641b

ceilometer/central/manager.py

@@ -16,8 +16,6 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from nova import manager
-
 from ceilometer import extension_manager
 from ceilometer.compute import resources
 from ceilometer.openstack.common import cfg
@@ -38,17 +36,15 @@ LOG = log.getLogger(__name__)
 PLUGIN_NAMESPACE = 'ceilometer.poll.central'
 
 
-class AgentManager(manager.Manager):
+class AgentManager(object):
     def __init__(self, host=None):
-        super(AgentManager, self).__init__(host=host)
+        super(AgentManager, self).__init__()
+        self.host = host
         self.resources = resources.Resources()
-
-    def init_host(self):
         self.ext_manager = extension_manager.ActivatedExtensionManager(
             namespace=PLUGIN_NAMESPACE,
             disabled_names=cfg.CONF.disabled_central_pollsters,
             )
-        return
 
     @staticmethod
     def publish_counters_from_one_pollster(ext, manager, context):