rgw: cleanup legacy task

this task was here for backward compatibility.
It's time to remove it in the next release.

Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>

roles/ceph-rgw/tasks/docker/start_docker_rgw.yml

@@ -22,21 +22,6 @@
   notify:
     - restart ceph rgws
 
-# For backward compatibility
-- name: disable old systemd unit ('ceph-rgw@'|'ceph-radosgw@radosgw.'|'ceph-radosgw@') if present
-  systemd:
-    name: "{{ item }}"
-    state: stopped
-    enabled: no
-    masked: yes
-    daemon_reload: yes
-  with_items:
-    - "ceph-rgw@{{ ansible_hostname }}"
-    - "ceph-radosgw@{{ ansible_hostname }}.service"
-    - "ceph-radosgw@radosgw.{{ ansible_hostname }}.service"
-    - ceph-radosgw@radosgw.gateway.service
-  ignore_errors: true
-
 - name: systemd start rgw container
   systemd:
     name: ceph-radosgw@rgw.{{ ansible_hostname }}.{{ item.instance_name }}