Fixed positioning of legend box

Fixed the position of the legend box, when using custom point sizes.

Author: Alfie Hopkin

src/plugins/plugin.legend.js

@@ -370,9 +370,8 @@ var Legend = Element.extend({
 					// Recalculate x and y for drawPoint() because its expecting
 					// x and y to be center of figure (instead of top left)
 					var radius = boxWidth * Math.SQRT2 / 2;
-					var offSet = radius / Math.SQRT2;
-					var centerX = x + offSet;
-					var centerY = y + offSet;
+					var centerX = x + (fontSize / 2);
+					var centerY = y + (fontSize / 2);
 
 					// Draw pointStyle as legend symbol
 					helpers.canvas.drawPoint(ctx, legendItem.pointStyle, radius, centerX, centerY);