Fix bug 900864 Quantum Manager flag for IP injection.

Re-uses FlatManager flat_injected flag to enable/disable
IP injection in QuantumManager.

Change-Id: I52c7a2c3aed452045cadb2282a59851c1083a812

nova/network/quantum/manager.py

@@ -504,6 +504,7 @@ def get_instance_nw_info(self, context, instance_id, instance_uuid,
                            'uuid': network['uuid'],
                            'bridge': '',  # Quantum ignores this field
                            'label': network['label'],
+                           'injected': FLAGS.flat_injected,
                            'project_id': net_tenant_id}
                 networks[vif['uuid']] = network