Remove database dump from nextcloud hook

The database will be backed up from the volume directly

nextcloud.sh

@@ -1,9 +1,7 @@
 pre() {
-  docker exec nextcloud_db_1 pg_dump -U postgres nextcloud > /tmp/nextcloud.sql
   docker exec -u 33 nextcloud_app_1 ./occ maintenance:mode --on
 }
 
 post() {
-  rm /tmp/nextcloud.sql
   docker exec -u 33 nextcloud_app_1 ./occ maintenance:mode --off
 }