Update backup.md

Author: antaljanosbenjamin

docs/en/operations/backup.md

@@ -23,7 +23,7 @@ title: 'Backup and Restore'
   DATABASE database_name [AS database_name_in_backup]
     [EXCEPT TABLES ...] |
   TEMPORARY TABLE table_name [AS table_name_in_backup] |
-  VIEW view_name [AS view_name_in_backup]
+  VIEW view_name [AS view_name_in_backup] |
   ALL [EXCEPT {TABLES|DATABASES}...] } [,...]
   [ON CLUSTER 'cluster_name']
   TO|FROM File('<path>/<filename>') | Disk('<disk_name>', '<path>/') | S3('<S3 endpoint>/<path>', '<Access key ID>', '<Secret access key>')