setup_sshd_config: remove useless start_sshd parameter

setup_sshd_config: remove useless start_sshd parameter

This controlled if we use reload-or-restart or try-reload-or-restart.
They differ in the following way:
> reload-or-restart - Reload one or more units if possible, otherwise
> start or restart
>
> try-reload-or-restart - Reload one or more units if possible,
> otherwise (re)start if active

Under PVE we normally need a running ssh for a node/cluster to work,
there isn't the case where it should be stopped, especially not for
this method which is normally called when setting up or joining a
cluster.
So always use 'reload-or-restart'.

Semantically reverts: 6c0e95b3

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>