fix postgres backup routine

tasks/backup.yaml

@@ -19,8 +19,8 @@
     stdin: "{{nextcloud_database_pass}}"
   when: nextcloud_database_type == "mysql"
 
-- name: drop postgresql database
-  shell: sudo -u postgres pg_dump -O
+- name: dump postgresql database
+  shell: sudo -u postgres pg_dump -O "{{nextcloud_database_name}}"
     > "{{nextcloud_backup_directory}}/{{_nextcloud_actual_version}}/database.pgsql"
   delegate_to: "{{ (nextcloud_database_host != 'localhost') | ternary(nextcloud_database_host,inventory_hostname) }}"
   when: nextcloud_database_type == "postgresql"