Avoid error if borderOpts.dash is undefined (#11907)

Author: HieroglypH

src/scales/scale.radialLinear.js

@@ -317,7 +317,7 @@ function drawRadiusLine(scale, gridLineOpts, radius, labelCount, borderOpts) {
   ctx.save();
   ctx.strokeStyle = color;
   ctx.lineWidth = lineWidth;
-  ctx.setLineDash(borderOpts.dash);
+  ctx.setLineDash(borderOpts.dash || []);
   ctx.lineDashOffset = borderOpts.dashOffset;
 
   ctx.beginPath();