fix(line): make copy of points data before reversing

Author: benurb

packages/line/src/Points.js

@@ -18,7 +18,7 @@ const Points = ({ points, symbol, size, borderWidth, enableLabel, label, labelYO
      * We reverse the `points` array so that points from the lower lines in stacked lines
      * graph are drawn on top. See https://github.com/plouc/nivo/issues/1051.
      */
-    const mappedPoints = points.reverse().map(point => {
+    const mappedPoints = points.slice(0).reverse().map(point => {
         const mappedPoint = {
             id: point.id,
             x: point.x,