修复bug

src/graphic/Service/LineService.js

@@ -175,7 +175,7 @@ export default class LineService {
     let newPoint = curvePointService.create(position);
     newPoint.setIndex(index);
     newPoint.setPointParent(vectorId);
-    curveLine.points.splice(index + 1, 0, newPoint);
+    curveLine.points.splice(index, 0, newPoint);
     for (let i = index + 1; i < curveLine.points.length; ++i) {
       curveLine.points[i].setIndex(i);
     }