Revert "fdo#72563 : PAGEREF field tag not preserved during Roundtrip"

This reverts commit 138bd3d656c30911d5f45a8b6804e50857f6b30c. See
comment 5 in the bugreport, the fix in its current form causes more
trouble than it fixes.

Conflicts:
	sw/qa/extras/ooxmlexport/ooxmlexport.cxx

Change-Id: I64f64f02a2e073b96e165c81bd2f85928e5527bc