Theme directory 16/panel of theme Delta has no size field

[archiebug]

using cinnamon desktop with the delta theme, a few warnings are being tossed into .xsessions-errors:

(nemo:8077): Gtk-WARNING **: 10:15:39.813: Theme directory 16/panel of theme Delta has no size field
(cinnamon:3762): Gtk-WARNING **: 10:15:36.818: Theme directory 16/panel of theme Delta has no size field

The index.theme file is missing some stuff.

solution:
update the intex.theme to include

[16/panel]
Context=Panel
Size=16
MinSize=8
MaxSize=16
Type=Scalable

The warning(s) should go away.