gtk3: re-enable when in backdrop and receive delete signal
gtk3: re-enable when in backdrop and receive delete signal

Change-Id: I845a3eda41263a07e1e69eb6ff37ff5ab2576905

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