Make Jitsi JVB work correctly with IPv6

Since the Jitsi Docker Compose stack does not properly take IPv6 into consideration, patch the JVB config to add mappings from the private IPv6 address of the Docker network to the public IPv6 address.

This should be the source of the reported problems with conferences with 3+ people.

roles/jitsi/tasks/main.yaml

@@ -110,6 +110,25 @@
     label: "{{ item.name }}"
   notify: restart jitsi web
 
+- name: deploy custom JVB configuration
+  ansible.builtin.template:
+    src: custom-jvb.conf.j2
+    dest: "{{ jitsi__config_dir }}/jvb/custom-jvb.conf"
+    mode: "0644"
+    owner: root
+    group: root
+  become: true
+  when: jitsi__jvb_advertise_ipv6s | length > 0
+  notify: restart jitsi jvb
+
+- name: remove unconfigured custom JVB configuration
+  ansible.builtin.file:
+    path: "{{ jitsi__config_dir }}/jvb/custom-jvb.conf"
+    state: absent
+  become: true
+  when: jitsi__jvb_advertise_ipv6s | length == 0
+  notify: restart jitsi jvb
+
 - name: make sure the coturn directory exists
   ansible.builtin.file:
     path: "{{ jitsi__base_dir }}/coturn"