FIX RenderMeshExample not having a material on mission start even if one was assigned to it in the mission file.

Engine/source/T3D/examples/renderMeshExample.cpp

@@ -107,6 +107,8 @@ bool RenderMeshExample::onAdd()
 
    // Add this object to the scene
    addToScene();
+   // Refresh this object's material (if any)
+   updateMaterial();
 
    return true;
 }