Capsule Upgrade Playbook が接続エラーで失敗する

Issue

• Capsule Upgrade Playbook が以下のエラーで失敗します。

    fatal: [capsule.example.com]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: 
    Failed to add the host to the list of known hosts (/usr/share/foreman-proxy/.ssh/known_hosts).rnAuthorized uses only. All 
    activity may be monitored and reported.nConnection to 10.20.30.40 closed by remote host.rnConnection to 10.20.30.40 
    closed.", "unreachable": true}