Default gateway on the admin network is set on node group network_interfaces rather than here

etc/kayobe/networks.yml

@@ -65,7 +65,6 @@ admin_oc_net_vlan: 41
 admin_oc_net_cidr: "10.{{ admin_oc_net_vlan }}.0.0/16"
 admin_oc_net_allocation_pool_start: "10.{{ admin_oc_net_vlan }}.160.1"
 admin_oc_net_allocation_pool_end: "10.{{ admin_oc_net_vlan }}.160.255"
-admin_oc_net_gateway: "10.{{ admin_oc_net_vlan }}.255.1"
 
 # Overcloud out-of-band management network IP information.
 oob_oc_net_vlan: 45