[FIX] add docker volume for custom PHP config

templates/nextcloud.yaml.j2

@@ -25,6 +25,7 @@ services:
 {% endfor %}
     volumes:
       - nextcloud:/var/www/html:z
+      - ./nextcloud-extra.ini:/usr/local/etc/php/conf.d/nextcloud-extra.ini:ro
     networks:
       default:
       inverseproxy_shared: