cp#1000016 DOCX/RTF import: fix RemoveLastParagraph() on Windows

(cherry picked from commit a56bfe734a7bed40a175e0eeb7e86e7006a83f83)

Signed-off-by: Andras Timar <andras.timar@collabora.com>

Conflicts:
	sw/qa/extras/rtfimport/rtfimport.cxx
	writerfilter/source/dmapper/DomainMapper_Impl.cxx

Change-Id: I3f9d69ddbb2144c60a724e4242128b65ae167455
Signed-off-by: Andras Timar <andras.timar@collabora.com>