Flag 'use_gateway' cannot be provided without gateway" error when discarding cluster changes

Environment configuration:
[root@nailgun ~]# shotgun2 short-report
cat /etc/fuel_build_id:
 417
cat /etc/fuel_build_number:
 417
cat /etc/fuel_release:
 9.0
cat /etc/fuel_openstack_version:
 mitaka-9.0

steps to reproduce:
1. create environment (default wizard settings), add some nodes and deploy the env
2. go to Networks tab, add a new node network group
3. click Show All Networks checkbox to observe all node network groups on the one page
4. click Load Deployed Settings button
5. delete created node group
6. go to dashboard and discard changes

Actual result:
Changes were not discarded, error message in console:
PUT http://172.16.17.43:8417/api/clusters/1/network_configuration/neutron 400 (Bad Request)
Uncaught TypeError: newNetworkConfiguration.get(...).get is not a function
PUT http://172.16.17.43:8417/api/clusters/1/network_configuration/neutron 400 (Bad Request)
Uncaught TypeError: newNetworkConfiguration.get(...).get is not a function

Expected result:
Changes were discarded