check_ceph_osd nor working with Proxmox/Ceph Nautilus

I've just upgraded our Proxmox cluster to 6.2 including the upgrade from Ceph Luminous to Nautilus.
All other checks (check_ceph_health, check_ceph_mon, check_ceph_df) still work as expected but check_ceph_osd is refusing to work.

I'm using the following command:
`/usr/lib/nagios/plugins/check_ceph_osd -i nagios --key /var/lib/nagios/ceph.client.nagios.keyring --host 10.55.0.1 --out`

followed by this error:
`OSD ERROR: 2020-08-26 09:32:03.862 7fbe53968700 -1 auth: unable to find a keyring on /etc/pve/priv/ceph.client.nagios.keyring: (2) No such file or directory
2020-08-26 09:32:03.862 7fbe53968700 -1 AuthRegistry(0x7fbe4c081ff8) no keyring found at /etc/pve/priv/ceph.client.nagios.keyring, disabling cephx`

I don't know why ceph is looking for a key in /etc/pve/priv/ceph.client.nagios.keyring
If I copy my key from /var/lib/nagios/ceph.client.nagios.keyring to /etc/pve/priv/ceph.client.nagios.keyring the command works as expected but only as user root. In Proxmox, `/etc/pve/priv` is a special cluster file system where all files are owned by root with no read permissions for any other user. Of course I would like to avoid running the check as root.

Keyring has been created with
`ceph auth get-or-create client.nagios mon 'allow r' osd 'allow r' > /var/lib/nagios/ceph.client.nagios.keyring`

Maybe thats the same problem as in issue #30 but worked in Luminous?