Non-string value for interface name leads os-net-config to exit ungracefully with TypeError: unhashable type: 'dict'

Non-string value for interface name leads os-net-config to exit ungracefully with TypeError: unhashable type: 'dict'
~~~
[root@overcloud-compute-0 ~]# os-net-config -v -c /etc/os-net-config/config.json
[2018/07/16 03:33:39 PM] [INFO] Using config file at: /etc/os-net-config/config.json
[2018/07/16 03:33:39 PM] [INFO] Ifcfg net config provider created.
[2018/07/16 03:33:39 PM] [INFO] Not using any mapping file.
[2018/07/16 03:33:40 PM] [INFO] Finding active nics
[2018/07/16 03:33:40 PM] [INFO] vxlan_sys_4789 is not an active nic
[2018/07/16 03:33:40 PM] [INFO] eth4 is an embedded active nic
[2018/07/16 03:33:40 PM] [INFO] eth3 is an embedded active nic
[2018/07/16 03:33:40 PM] [INFO] eth2 is an embedded active nic
[2018/07/16 03:33:40 PM] [INFO] eth1 is an embedded active nic
[2018/07/16 03:33:40 PM] [INFO] eth0 is an embedded active nic
[2018/07/16 03:33:40 PM] [INFO] lo is not an active nic
[2018/07/16 03:33:40 PM] [INFO] br-ex is not an active nic
[2018/07/16 03:33:40 PM] [INFO] docker0 is not an active nic
[2018/07/16 03:33:40 PM] [INFO] ovs-system is not an active nic
[2018/07/16 03:33:40 PM] [INFO] br-int is not an active nic
[2018/07/16 03:33:40 PM] [INFO] br-tun is not an active nic
[2018/07/16 03:33:40 PM] [INFO] No DPDK mapping available in path (/var/lib/os-net-config/dpdk_mapping.yaml)
[2018/07/16 03:33:40 PM] [INFO] Active nics are ['eth0', 'eth1', 'eth2', 'eth3', 'eth4']
[2018/07/16 03:33:40 PM] [INFO] nic5 mapped to: eth4
[2018/07/16 03:33:40 PM] [INFO] nic4 mapped to: eth3
[2018/07/16 03:33:40 PM] [INFO] nic3 mapped to: eth2
[2018/07/16 03:33:40 PM] [INFO] nic2 mapped to: eth1
[2018/07/16 03:33:40 PM] [INFO] nic1 mapped to: eth0
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 254, in main
    obj = objects.object_from_json(iface_json)
  File "/usr/lib/python2.7/site-packages/os_net_config/objects.py", line 47, in object_from_json
    return OvsBridge.from_json(json)
  File "/usr/lib/python2.7/site-packages/os_net_config/objects.py", line 543, in from_json
    fail_mode=fail_mode)
  File "/usr/lib/python2.7/site-packages/os_net_config/objects.py", line 500, in __init__
    nm_controlled, onboot)
  File "/usr/lib/python2.7/site-packages/os_net_config/objects.py", line 265, in __init__
    if name in mapped_nic_names:
TypeError: unhashable type: 'dict'
~~~

This happens when the input value is:
~~~
[root@overcloud-compute-0 ~]# cat /etc/os-net-config/config.json
{"network_config": [{"addresses": [{"ip_netmask": "192.168.24.11/24"}], "dns_servers": ["192.168.24.1"], "name": "nic1", "routes": [{"ip_netmask": "169.254.169.254/32", "next_hop": "192.168.24.1"}, {"default": true, "next_hop": "192.168.24.1"}], "type": "interface", "use_dhcp": false}, {"members": [{"name": "nic2", "primary": true, "type": "interface"}, {"addresses": [{"ip_netmask": "172.16.2.9/24"}], "type": "vlan", "vlan_id": 901}, {"addresses": [{"ip_netmask": "172.18.0.17/24"}], "type": "vlan", "vlan_id": 903}, {"addresses": [{"ip_netmask": "172.16.0.8/24"}], "type": "vlan", "vlan_id": 902}], "name": {get_input: bridge_name}, "type": "ovs_bridge", "use_dhcp": false}, {"defroute": false, "name": "nic3", "type": "interface", "use_dhcp": false}, {"defroute": false, "name": "nic4", "type": "interface", "use_dhcp": false}]}
~~~

Which in turn may happen if an administrator upgrades from an older version of tripleo to a newer version and forgets to change the bridge name in the templates from '{get_input: bridge_name}' to 'bridge_name'.
~~~
              -
                type: ovs_bridge
                name: {get_input: bridge_name}
                use_dhcp: false
                members:
~~~
vs
~~~
              -
                type: ovs_bridge
                name: bridge_name
                use_dhcp: false
                members:
~~~