[GNC] piecharts/linecharts turned blank in reports after upgrade

[Dong Lin]

I am trying to upgrade from 3.8 to 4.6. But found that piecharts and
linecharts in reports have turned blank. The associated tables are present
though.

Attempted to perform a binary search in master, and found the latest
working commit is 63232f388.


8024f44bc Sat Apr 25 15:40:07 2020 -0700                 Remove leftover
webkit2 conditional.
63232f388 Sat Apr 25 14:40:57 2020 -0700                 Merge Jean
Laroche's 'Fix-3-SX-Problems' into maint


Unfortunately 8024f44bc came from the maint branch and was merged with
over a hundred other commits.  I am not sure how to narrow it down.
Reverting one of them resulted in lots of conflicts that I dont know how
to resolve.

I figured the problem has to be related to my environment as no one else
has brought up the issue. My virtual desktop is
driven by a VNC server (Ubuntu 20.04 LTS).  It's not directly associated
with a hardware graphics card with a physical cable to the monitor.