fdo#79303: Revert "fdo#70861 SwToSfxPageDescAttr: fix call to ...

... SvxExtParagraphTabPage"

This reverts commit 5ce19ddcb6595c71980aecfa1e8c0827343159a4.

It is now simply wrong to claim that a SID_ATTR_PARA_PAGENUM item with
value 0 is set, when that is a valid offset value.

SwTxtShell::Execute() will call SfxToSwPageDescAttr() which pulls the
SID_ATTR_PARA_PAGENUM out of the item set and sets it.

Change-Id: If5a155c2874486b3ef7d01883fe73f8e5fca46fe
Signed-off-by: Andras Timar <andras.timar@collabora.com>
(cherry picked from commit d12fc79394842951807ab8c58a810cd9c5848cb7)
Reviewed-on: https://gerrit.libreoffice.org/13175
Tested-by: Caolán McNamara <caolanm@redhat.com>
Reviewed-by: Eike Rathke <erack@redhat.com>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>