Fix a typo.

defaults/main.yml

@@ -26,11 +26,11 @@ sysctl_custom_options: []
 #   sysctlfile_state: '{{ sysctl_custom_file_state }}'
 
 ubuntu_configure_additional_interfaces: false
-ubuntu_second_int_name: "enp8s0"
+ubuntu_second_int_name: "enp4s0"
 ubuntu_netplan_interfaces:
   - name: "{{ ubuntu_second_int_name }}"
     dhcp4: true
-    mtu: "{{ ansible_enp8s0.mtu }}"
+    mtu: 1500
 disable_ipv6: false
 ipv6_sysctl_value: 1
 ipv6_sysctl_file: /etc/sysctl.d/10-ipv6-disable.conf