facts: add a retry on get current fsid task
facts: add a retry on get current fsid task

sometimes it can happen the following task fails:

```
TASK [ceph-facts : get current fsid] *******************************************
task path: /home/jenkins-build/build/workspace/ceph-ansible-prs-dev-centos-container-update/roles/ceph-facts/tasks/facts.yml:78
Wednesday 19 June 2019  18:12:49 +0000 (0:00:00.203)       0:02:39.995 ********
fatal: [mon2 -> mon1]: FAILED! => changed=true
  cmd:
  - timeout
  - --foreground
  - -s
  - KILL
  - 600s
  - docker
  - exec
  - ceph-mon-mon1
  - ceph
  - --cluster
  - ceph
  - daemon
  - mon.mon1
  - config
  - get
  - fsid
  delta: '0:00:00.239339'
  end: '2019-06-19 18:12:49.812099'
  msg: non-zero return code
  rc: 22
  start: '2019-06-19 18:12:49.572760'
  stderr: 'admin_socket: exception getting command descriptions: [Errno 2] No such file or directory'
  stderr_lines: <omitted>
  stdout: ''
  stdout_lines: <omitted>
```

not sure exactly why since just before this task, mon1 seems to be well
UP otherwise it wouldn't have passed the task `waiting for the
containerized monitor to join the quorum`.

As a quick fix/workaround, let's add a retry which allows us to get
around this situation:

```
TASK [ceph-facts : get current fsid] *******************************************
task path: /home/jenkins-build/build/workspace/ceph-ansible-scenario/roles/ceph-facts/tasks/facts.yml:78
Thursday 20 June 2019  15:35:07 +0000 (0:00:00.201)       0:03:47.288 *********
FAILED - RETRYING: get current fsid (3 retries left).
changed: [mon2 -> mon1] => changed=true
  attempts: 2
  cmd:
  - timeout
  - --foreground
  - -s
  - KILL
  - 600s
  - docker
  - exec
  - ceph-mon-mon1
  - ceph
  - --cluster
  - ceph
  - daemon
  - mon.mon1
  - config
  - get
  - fsid
  delta: '0:00:00.290252'
  end: '2019-06-20 15:35:13.960188'
  rc: 0
  start: '2019-06-20 15:35:13.669936'
  stderr: ''
  stderr_lines: <omitted>
  stdout: |-
    {
        "fsid": "153e159d-7ade-42a7-842c-4d04348b901e"
    }
  stdout_lines: <omitted>
```

Signed-off-by: Guillaume Abrioux <30a9df5a0293a6108675377fa1673f7aa713f915@redhat.com>

ceph/ceph-ansible,ceph/ceph-ansible