rolling_update: remove 'ignore_errors'

rolling_update: remove 'ignore_errors'

There's no need to use `ignore_errors: true` on these tasks.

Using a loop on the task stopping mon daemons allows us to avoid
duplicating this task, the `ignore_errors` isn't needed here because it
won't fail the playbook if one of the ID doesn't exist (shortname vs. fqdn)

Using the right condition on the task starting the mgr daemon allows us
to avoid using an `ignore_errors: true` as well.

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