Comment 1 for bug 1674251

I should add, I also do not have the nvidia drivers installed:

$ dpkg -l *nouveau*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-=============================-===================-===================-================================================================
ii libdrm-nouveau2:amd64 2.4.70-1~ubuntu16.0 amd64 Userspace interface to nouveau-specific kernel DRM services -- r
 ~ $ dpkg -l *nvidia*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-=============================-===================-===================-================================================================
un nvidia-common <none> <none> (no description available)
un nvidia-legacy-340xx-vdpau-dri <none> <none> (no description available)
un nvidia-prime <none> <none> (no description available)
un nvidia-vdpau-driver <none> <none> (no description available)
 ~ $