Light : fix dirty propagation issue causing IPR to not update
Light : fix dirty propagation issue causing IPR to not update

hradec/gaffer,johnhaddon/gaffer,lucienfostier/gaffer,ImageEngine/gaffer,johnhaddon/gaffer,ImageEngine/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer,lucienfostier/gaffer,lucienfostier/gaffer,andrewkaufman/gaffer,boberfly/gaffer,johnhaddon/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,appleseedhq/gaffer,appleseedhq/gaffer,hradec/gaffer,hradec/gaffer,boberfly/gaffer,GafferHQ/gaffer,hradec/gaffer,appleseedhq/gaffer,boberfly/gaffer,lucienfostier/gaffer,andrewkaufman/gaffer,boberfly/gaffer,appleseedhq/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,GafferHQ/gaffer,GafferHQ/gaffer,hradec/gaffer,ImageEngine/gaffer