bump gl-scatter2d-sdf to 1.3.9

Author: etpinard

package.json

@@ -74,7 +74,7 @@
     "gl-plot3d": "^1.5.4",
     "gl-pointcloud2d": "^1.0.0",
     "gl-scatter2d": "^1.2.2",
-    "gl-scatter2d-sdf": "1.3.4",
+    "gl-scatter2d-sdf": "^1.3.9",
     "gl-scatter3d": "^1.0.4",
     "gl-select-box": "^1.0.1",
     "gl-shader": "4.2.0",