Update babylon.polygonmesh.ts

Babylon/Mesh/babylon.polygonmesh.ts

@@ -153,7 +153,7 @@
             });
 
             result.setVerticesData(VertexBuffer.PositionKind,positions,  updatable);
-            result.setVerticesData(VertexBuffer.NormalKind,  updatable);
+            result.setVerticesData(VertexBuffer.NormalKind,normals  updatable);
             result.setVerticesData(VertexBuffer.UVKind,uvs, updatable);
             result.setIndices(indices);