fix crash on export of ooo30155-1.sxw to odt
fix crash on export of ooo30155-1.sxw to odt

Change-Id: I1dd087ea6803f29756e1b78385a4a98f7378e616

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