Commit 3d1bb76e (tdf#112109 sw: split
section frames inside table cells, ignore nested tables, 2017-08-31)
explicitly disabled this, but the underlying problem is now fixed with
commit ec262cbc (tdf#112160 sw: audit
GetNextLayoutLeaf() calls in SwFrame::GetNextSctLeaf(), 2017-09-04), so
we can have it again.

Change-Id: Ic17c4921de2c69e4cc16ae82cfed58d096879db7