DOCX import: close rPrChange properly.

Call endtrackchanges when rPrChange ends so the
corresponding redline will be removed.

Conflicts:
	sw/qa/extras/ooxmlimport/ooxmlimport.cxx
Reviewed on:
	https://gerrit.libreoffice.org/7194

Change-Id: I4091d7b54e0a74f3158cc979f210577a2dc29783