vcldemo: fix --widgets crash-on-exit
vcldemo: fix --widgets crash-on-exit

Window ( 7VclVBox()) with live children destroyed:  7ToolBox() 10PushButton(Click me; go on)

Change-Id: I7b95198e24ea4d6ab085705096421219b3e16904

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core