refstack: fix backup script typo

This got copied from another command that also had this typo.

Also, don't bother backing up the on-disk backups, as we backup
directly via the stream dumps.

Change-Id: Ie200a29eec2b1a0725a8872ab548bcb0f26980e6

inventory/service/host_vars/refstack01.openstack.org.yaml

@@ -5,3 +5,5 @@ letsencrypt_certs:
 borg_backup_excludes_extra:
   # live db files
   - /var/lib/refstack/db
+  # on-disk backups
+  - /var/backups/refstack-mariadb

playbooks/roles/refstack/tasks/main.yaml

@@ -150,5 +150,5 @@
       copy:
         content: >-
             /usr/local/bin/docker-compose -f /etc/refstack-docker/docker-compose.yaml exec -T mariadb
-            bash -c '/usr/bin/mysqldump --skip-extended-insert --databases gitea --single-transaction -uroot -p"$MYSQL_ROOT_PASSWORD"'T_PASSWORD"'
+            bash -c '/usr/bin/mysqldump --skip-extended-insert --databases refstack --single-transaction -uroot -p"$MYSQL_ROOT_PASSWORD"'
         dest: /etc/borg-streams/mysql