Resolves: tdf#90301 string access out of bounds
Resolves: tdf#90301 string access out of bounds

Apparently yet another leftover of UniString to OUString conversion
where with UniString out-of-bounds accesses didn't harm and returned
NIL.

Change-Id: Id88456a52df3fc8cdaf90d9d509e327b96269808

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