Update comment to reality... many properties now, not one.

Change-Id: Icc81d3067969d1d61182865d36ecabec4e7f85b7
Reviewed-on: https://gerrit.libreoffice.org/9551
Reviewed-by: Lionel Elie Mamane <lionel@mamane.lu>
Tested-by: Lionel Elie Mamane <lionel@mamane.lu>