unnecessary to check for null before delete
unnecessary to check for null before delete

Change-Id: I82b5c5ced8a4f0e719d1aeffed86845b9db1b68b

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