Faulty `/var/spool/collector-sidecar/nxlog` reference in sidecar guide

[oscarlofwenhamn]

Context

In the Graylog Sidecar docs (specifically the section regarding NXlog on Ubuntu | CentOS collectors) there is a command that I suspect is deprecated:

$ sudo chown -R nxlog.nxlog /var/spool/collector-sidecar/nxlog

The directory in question is no longer present, and I am thinking the corresponding directory may simply be the /var/spool/nxlog directory (which might be "owned" by nxlog.nxlog already).

Expected Content

If the command truly is deprecated, the instructions should be updated with the correct line.

I'd be happy to sort out a PR for this, but I need it confirmed that it is correct first.