NixOS as LXC Container for ProtonMail Bridge

Tested on/with:

• SFOS 4.5.0.24 on Xperia 10 III
• Harbour Containers 0.8.1-1.3.1.jolla
• lxc-templates-desktop 1.4.-1.1.1.jolla

Pre-requisites:

• Remote login on the SFOS with devel-su rights (I would not try the below with fingerterm...)
• Fresh SFOS instance using the "Distribution" (tempate) "nixos" from Harbour Containers