Revert "fix Worksheet.Cells by now allowing TableSheet..." fdo#70079

This reverts commit 70aff4a7f7abe0c768238733ca8900b746e60189.

Change-Id: I8f8b423353ae1a825be91bd94308e87844948525
Signed-off-by: Noel Power <noel.power@suse.com>