Revert "Make n-net refuse to start unless using CellsV1"

This reverts commit c07046edeee562142c90aa3cadd4bdc47b0a15da.

Trove's CI jobs don't currently work with Neutron due to
bug 1629133 so this is a temporary revert until the Trove CI/infra
networking situation gets sorted out. We have agreement from
the Trove PTL to revert this revert after the o-2 milestone on
2016/12/15.

Change-Id: Ia4fc545a10c7c16532aefd73818dd7d90c9c271b
Related-Bug: #1629133

nova/cmd/network.py

@@ -25,7 +25,7 @@ from nova.cmd import common as cmd_common
 from nova.conductor import rpcapi as conductor_rpcapi
 import nova.conf
 from nova import config
-from nova.i18n import _LE, _LW
+from nova.i18n import _LW
 from nova import objects
 from nova.objects import base as objects_base
 from nova import service
@@ -39,12 +39,6 @@ LOG = logging.getLogger('nova.network')
 def main():
     config.parse_args(sys.argv)
     logging.setup(CONF, "nova")
-
-    if not CONF.cells.enable:
-        LOG.error(_LE('Nova network is deprecated and not supported '
-                      'except as required for CellsV1 deployments.'))
-        return 1
-
     utils.monkey_patch()
     objects.register_all()
 

nova/tests/unit/cmd/test_cmd_db_blocks.py

@@ -51,7 +51,6 @@ class ComputeMainTest(test.NoDBTestCase):
                               db.api.instance_get, 1, 2)
 
     def test_network_main_blocks_db(self):
-        self.flags(enable=True, group='cells')
         with restore_db():
             self._call_main(network)
             self.assertRaises(exception.DBNotAllowed,

releasenotes/notes/nova-network-only-for-cellsv1-dfb72fb1d3339bb3.yaml

@@ -1,6 +0,0 @@
----
-deprecations:
-  - Nova network was deprecated in Newton and is no longer
-    supported for regular deployments in Ocata. The network
-    service binary will now refuse to start, except in the special
-    case of CellsV1 where it is still required to function.