Export fails due to how shapes are handled

[daswisher]

Adding things like a star to the page causes it to crash during export. This is within the isCircle function where it calls var points = layer.layers()[0].allCurvePoints(); on helpers.ts (line 82).

Commenting out the code on the js file within the plugin bundle (lines 1113-1121) seemed to fixed the issue for now, but it means I can't add any other shapes aside from rectangles and circles.

Sketch Version: 51.3