The task in charge of activating new osd is skipped because
`devices` is populated with the devices being added only.
It means it doesn't enter the condition since the length of `devices` is less
than the number of activated osds.

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1906293



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