Synfig Gradient Bug 3

SIF files: curve-c-loop.sif and curve-c-loop-zigzag.sif show that the gradient bug I fixed a couple of days ago for linear gradients also shows up on curved gradients:

How they render:

The thin white lines shouldn't be there. Applying a very similar patch fixes the problem:

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dooglus > synfig > gradient bugs > curve gradients