remove the unused variable in mariabackup

Remove the unused variable "mariadb_backup_database_address"

Change-Id: If30b166160136c32dd0b892e4093b1798662e872

ansible/roles/mariadb/defaults/main.yml

@@ -111,7 +111,6 @@ mariabackup_image_full: "{{ mariabackup_image }}:{{ mariabackup_tag }}"
 mariadb_backup_host: "{{ groups['mariadb'][0] }}"
 mariadb_backup_database_schema: "PERCONA_SCHEMA"
 mariadb_backup_database_user: "backup"
-mariadb_backup_database_address: "{{ database_address }}"
 mariadb_backup_type: "full"
 
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