Fix convert-to-NIA stillImage check

For example, this GIF image:
which is 'disassembled' here:
only has one frame, regardless of how the GIF codec implementation deals
with the LZW-compression error. It is not an animated image.
Nonetheless, frameInfos.size() returns 1, not 0, so prior to this
commit, "stillImage = frameInfos.empty()" assigned false, not true.

See also this Wuffs (not Skia) commit:

Bug: None
Change-Id: Ia69a486abe5c2caa7488c55a37c403e7660ff168
Commit-Queue: Leon Scroggins <>
Reviewed-by: Leon Scroggins <>
1 file changed