There was a problem for some documents(containing table on page spanning across multiple pages
& pages having different Header-Footer type), during export Invalid sectPr was getting added
because of wrong condition check in the code.
Because of this:
1)Table row data was getting displayed twice after RT.
2)Increased number of pages after RT.
3)Header & footer were also divided into sections (like: Header-Section1 Footer-Section1 & Header-Section2 Footer-Section2).

Conflicts:
	sw/qa/extras/ooxmlexport/ooxmlexport.cxx
Reviewed on:
	https://gerrit.libreoffice.org/7440

Change-Id: I6c07e47321353e84af306c6285702852303ccee0