Commit 17e51f42 (DOCX import: first page
header should always set default headers as well, 2014-11-21) turned on
header/footer of follow page styles of first page styles when the first
page style had the header/footer turned on, but failed to consider if
<w:titlePg> is present or not. When it's not present, the first page
header/footer should be ignored.

An additional problem is that by the time
DomainMapper_Impl::PushPageHeaderFooter() is called, <w:titlePg> is not
parsed yet, so we can't act accordingly.

Fix the problem by moving the check to
SectionPropertyMap::PrepareHeaderFooterProperties(), which runs at the
end of the section properties, where all required info is available,
there we can just check for m_bTitlePage.

This allows reverting the two changes to existing testcases in
CppunitTest_sw_ooxmlexport6 from the original commit as a side-effect.

Change-Id: Ic628adab99a4b148fcfd66ca39d0cf81eb7dd9f1
Reviewed-on: https://gerrit.libreoffice.org/50014Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Jenkins <ci@libreoffice.org>