Assert when enabling shadows in lights example

Steps to reproduce:

1. Enable castsShadows in all lights in lights example
2. Start the example
3. Disable point light

Expected result:

Point light gets disabled.

Actual result:

ASSERT: "inLight->m_lightType != QSSGRenderLight::Type::Directional" in file [+C:\dev\qtbuilds\qtbuild215x\qtquick3d\src\runtimerender\rendererimpl\qssgrendererimpllayerrenderdata.cpp, line 465+|c:\dev\qtbuilds\qtbuild215x\qtquick3d\src\runtimerender\rendererimpl\qssgrendererimpllayerrenderdata.cpp, line 465]