Added `cgroupsns` to jail, otherwise you get this failure:
```
Mon Mar 6 14:46:05 2023 user.err : jail: Not using namespaces, capabilities or seccomp !!!
```
Error is here, seems to indicate that we're running a jail without using any capability.
https://lxr.openwrt.org/source/procd/jail/jail.c#L2847
Decided to use minimal effort approach
Signed-off-by: BackSlasher <nitz.raz@gmail.com>
This commit is largely based on the work from Daniel Dickinson in
PR #2096 which was never merged. I tweaked it in a number of ways.
All bugs with this package are mine, not his.
Signed-off-by: Aaron Curley <accwebs@gmail.com>