Merge pull request #1404 from vousk/patch_arrayIteration3

changed Mesh.Center for environnement where array prototype is modified

src/Mesh/babylon.mesh.ts

@@ -2603,7 +2603,7 @@
          * Returns a Vector3, the center of the `{min:` Vector3`, max:` Vector3`}` or the center of MinMax vector3 computed from a mesh array.
          */
         public static Center(meshesOrMinMaxVector): Vector3 {
-            var minMaxVector = meshesOrMinMaxVector.min !== undefined ? meshesOrMinMaxVector : Mesh.MinMax(meshesOrMinMaxVector);
+            var minMaxVector = (meshesOrMinMaxVector instanceof Array) ? BABYLON.Mesh.MinMax(meshesOrMinMaxVector) : meshesOrMinMaxVector;
             return Vector3.Center(minMaxVector.min, minMaxVector.max);
         }