* Stop adding an opaque alpha channel to API node images
bytesio_to_image_tensor converted every downloaded image to RGBA, so nodes
whose API returns no transparency still emitted a 4 channel IMAGE. Keep the
alpha when the decoded image has one, stay RGB when it does not.
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Signed-off-by: bigcat88 <bigcat88@icloud.com>
Co-authored-by: bigcat88 <bigcat88@icloud.com>