Otherwise, a Database field in a paragraph which is non-empty would
force the paragraph to be visible, regardless of HiddenPara field
telling it to be hidden.

Regression from commit db04be03

Change-Id: I21807e22bd339fd1ea0aaa3b382579f688903418
Reviewed-on: https://gerrit.libreoffice.org/59792
Tested-by: Jenkins
Reviewed-by: Michael Stahl <Michael.Stahl@cib.de>