Update lxd-privilege-escalation.md

[roh4]

Error: unknown command "build-lxd" for "distrobuilder"

Did you mean this?
        build-lxc

Run 'distrobuilder --help' for usage.
Failed running distrobuilder: unknown command "build-lxd" for "distrobuilder"

Did you mean this?
        build-lxc

[carlospolop]

Hi @roh4 taking a quick look on the internet it looks like both options are used so maybe it depends on the version of distrobuilder used. Therefore, it makes more sense to suggest both more than changing one for the other