#1063 improper updated GTK colors

[Robert von Könemann]

pcmanfm gtk3 ver 1.2.5 and before, also gtk2 and qt version (when qt is set to use gtk theme).
running archlinux.

to reproduce, install pywal, run pywal -t -i /path/to/some/wallpaper.jpg
in lxappearance, set wal as colorscheme,
start pcmanfm,
run pywal again, with another image.
watch pcmanfwm for a few seconds

the issue:
when applying another gtk colorscheme,the correct settings DO NOT GET APPLIED to the background color of the file manager window. All other parts of pcmanfm get colorized apporpriately.

For use with a dynamic theming tool (pywal) it would be nice, if pcmanfm also applied the background image correctly, without the need of a restart of pcmanfm

[Robert von Könemann]

To clarify, the issue does NOT appear in GTK3 version, my bad. GTK3 version does not update at all.

I attached a screenshot to show the issue