misc/backup_files: Added variable backup_name as alternative of name by domain

roles/misc/backup_files/defaults/main.yml

@@ -1,9 +1,10 @@
 ---
 
-# domain: backup.example
-backup_directory: "{{ global_webservers_directory }}/{{ domain }}"
+# domain: backup.example # required if backup_name is not given
+backup_name: "{{ domain }}"
+backup_directory: "{{ global_webservers_directory }}/{{ backup_name }}"
 
-backup_script: "{{ backup_files_scripts_directory }}/{{ domain }}"
+backup_script: "{{ backup_files_scripts_directory }}/{{ backup_name }}"
 
 before_backup_command: ""
 after_backup_command: ""