[libvirt_manager] Honor network mtu in dnsmasq config

When creating a Libvirt network even with custom mtu,
dnsmasq was providing default mtu(1500) to the VMs.
This patch fixes it by configuring option:mtu as per
the network facts.

Signed-off-by: Yatin Karel <[email protected]>

Author: karelyatin

roles/libvirt_manager/tasks/create_networks.yml

@@ -156,6 +156,9 @@
       {% if _no_prefix_name not in _default_gw_net -%}
       - "option:router"
       {% endif -%}
+      {% if ansible_facts[_name].mtu is defined -%}
+      - "option:mtu,{{ ansible_facts[_name].mtu }}"
+      {% endif -%}
     _dns_listener:
       - "{{ ansible_facts[_name].ipv4.address | default('') }}"
       - "{{ _ipv6.address | default('') }}"