When normally editing curves, deleting the last keyframe also deletes the curve. Thus if for some reason it didn't happen, e.g. maybe due to removing keys directly via Python, skip the bad curve instead of resetting the channel to zero.
When normally editing curves, deleting the last keyframe also deletes the curve. Thus if for some reason it didn't happen, e.g. maybe due to removing keys directly via Python, skip the bad curve instead of resetting the channel to zero.