fix an OOXML chart validation error
fix an OOXML chart validation error

Change-Id: Ic91f6179b663afb59700f85ea48720dc9b14f372

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