add sys_nice and sys_nice_admin capabilities to an LXC on Proxmox 4.4

[titux]

Hi there,
I have searched a lot on google but couldn't find any specific (and trusty)procedure to add capabilities to a LXC on proxmox. (I need to install Freeswitch)

I already tried this (closer post I found to what I need):
https://forum.proxmox.com/threads/lxc-capabilities.23964/

Tried replacing CAP_NET_BIND_SERVICE,CAP_NET_BROADCAST with CAP_SYS_NICE,CAP_SYS_ADMIN.
NO LUCK..


Thanks for any help!
Regards
Hector