fdo#72163 belts and suspenders
fdo#72163 belts and suspenders

1) Do not dispose m_xComposer, might still be used by our m_pCache

2) Do not create a new m_xComposer if the previous one will do, so
   that we do not gratiously use a different one than our m_pCache.

Change-Id: I6540c035c9159017c694b36e676721ec3e42db51

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