[PVE-User] add default mount options to lxc containers

[Marc Cousin]

Hi,

I'm using LXC on servers which have storage with battery, so I'd like to
mount those filesystems with nobarrier. Is there a way I can specify
this mount option to containers (all containers at once would be even
better of course). I'm using LVM-Thin/ext4 containers (not shared
filesystems).

Regards.
Marc