Uptime missing when running in docker container

[lpic10]

Bug report

System info:

telegraf 1.6 running inside docker (CentOS Linux release 7.3.1611)
host: RHEL 7.4

Telegraf 1.6 is not retrieving the uptime information when running inside the container from some hosts.

Possibly related to issue shirou/gopsutil#507 and recent gops update

[danielnelson]

Can you check if the upstream bugfix solves the issue? I think this can probably wait for 1.7, which would be safer than pulling in a new release of gopsutil.

[lpic10]

Yes, it seems to do the trick.
As telegraf is using gopsutils just one commit behind this one, I've opened a PR to update to it. So should be safe to apply to 1.6