fixed volume for new nextcloud installations

docker-compose.yml

                 aliases:
                     - nextcloud.main.internal.docker
         volumes:
-            - ./data/nextcloud/apps:/var/www/html/apps
+            - ./data/nextcloud/custom_apps:/var/www/html/custom_apps
             - ./data/nextcloud/config:/var/www/html/config
             - ./data/nextcloud/data:/var/www/html/data
         ports: