sw: SwXAutoStyle::mpSet is read-only
sw: SwXAutoStyle::mpSet is read-only

... because it is an alias to the item set that is stored in the core
auto-style cache, which must _not_ be modified.

So remove the implementation of SwXAutoStyle::setPropertiesToDefault().

(regression from commit 7d9bb549d498d6beed2c4050c402d09643febdfa)

Change-Id: If529862d14a1c1e700ac898964560f386bf488f8

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