gtk3: remove obsolete forced background rendering
gtk3: remove obsolete forced background rendering

Change-Id: I3fabfcee9166d2b32dbadaedba6d364ae1a7559e

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