container/registry: use password from stdin

Pass the password variable via stdin for the registry login
authentication.
This allows to remove the no_log statement and see the task output
without displaying the password value.
Signed-off-by: Dimitri Savineau <dsavinea@redhat.com>

roles/ceph-container-common/tasks/registry.yml

 ---
 - name: container registry authentication
-  command: '{{ container_binary }} login -u {{ ceph_docker_registry_username }} -p {{ ceph_docker_registry_password | quote }} {{ ceph_docker_registry }}'
+  command: '{{ container_binary }} login -u {{ ceph_docker_registry_username }} --password-stdin {{ ceph_docker_registry }}'
+  args:
+    stdin: '{{ ceph_docker_registry_password }}'
+    stdin_add_newline: no
   changed_when: false
-  no_log: true
   environment:
     HTTP_PROXY: "{{ ceph_docker_http_proxy | default('') }}"
     HTTPS_PROXY: "{{ ceph_docker_https_proxy | default('') }}"