After minor update, new compute nodes fail to deploy

Issue

• Adding new compute nodes to existing overcloud fails. Error below can be seen on affected compute node(s):

[2019/07/10 09:10:50 AM] [WARNING] Config file failed schema validation at network_config/2:
    {'persist_mapping': False, 'device': 'eno2', 'addresses': [{'ip_netmask': ''}], 'nic_mapping': None, 'routes': [{'default': True, 'next_hop': 'x.x.x.x'}], 'type': 'vlan', 'vlan_id': 205, 'mtu': 1500} is not valid under any of the given schemas
  Sub-schemas tested and not matching:
  - items/oneOf/vlan/addresses/items/ip_netmask/oneOf: '' is not valid under any of the given schemas
  -- items/oneOf/vlan/addresses/items/ip_netmask/oneOf/ip_cidr_string/oneOf: '' is not valid under any of the given schemas
  --- items/oneOf/vlan/addresses/items/ip_netmask/oneOf/ip_cidr_string/oneOf/ipv4_cidr_string/pattern: '' does not match '^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)/(3[0-2]|[1-2][0-9]|[0-9])$'
  --- items/oneOf/vlan/addresses/items/ip_netmask/oneOf/ip_cidr_string/oneOf/ipv6_cidr_string/pattern: '' does not match '^(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:))/(12[0-8]|1[0-1][0-9]|[1-9][0-9]|[0-9])$'
  -- items/oneOf/vlan/addresses/items/ip_netmask/oneOf/param/oneOf: '' is not valid under any of the given schemas
  --- items/oneOf/vlan/addresses/items/ip_netmask/oneOf/param/oneOf/0/type: '' is not of type 'object'
  --- items/oneOf/vlan/addresses/items/ip_netmask/oneOf/param/oneOf/1/type: '' is not of type 'object'
  -- items/oneOf/vlan/addresses/items/ip_netmask/oneOf/2/type: '' is not of type 'object'
...truncated...
[2019/07/10 09:10:50 AM] [INFO] nic5 mapped to: ens3f0
Traceback (most recent call last):
  File "/bin/os-net-config", line 10, in <module>
    sys.exit(main())
  File "/usr/lib/python2.7/site-packages/os_net_config/cli.py", line 269, in main
    obj = objects.object_from_json(iface_json)
  File "/usr/lib/python2.7/site-packages/os_net_config/objects.py", line 45, in object_from_json
    return Vlan.from_json(json)
  File "/usr/lib/python2.7/site-packages/os_net_config/objects.py", line 432, in from_json
    opts = _BaseOpts.base_opts_from_json(json)
  File "/usr/lib/python2.7/site-packages/os_net_config/objects.py", line 343, in base_opts_from_json
    addresses.append(Address.from_json(address))
  File "/usr/lib/python2.7/site-packages/os_net_config/objects.py", line 247, in from_json
    ip_netmask = _get_required_field(json, 'ip_netmask', 'Address')
  File "/usr/lib/python2.7/site-packages/os_net_config/objects.py", line 95, in _get_required_field
    raise InvalidConfigException(msg)
os_net_config.objects.InvalidConfigException: Address JSON objects require 'ip_netmask' to be configured.

• The only changes made since the last successful scale out were increasing the node count and performing a minor update