scripts/vps-rst: make VE_VETH_DEVS optional

It is empty in case CT does not have any veth devices.

https://bugzilla.openvz.org/show_bug.cgi?id=2659

[kir@openvz.org: modify var description accordingly]

Reported-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
1 file changed