the paste special listener listens to owner changed, but expects
the owner changed event to contain the new contents, while the
original code expected getContents to be explicitly called to get
the new contents. So on owner changed always return the up to
date contents

Change-Id: Iaa7df2c01d360c3c5831b2258b4c2d41740fdffc
(cherry picked from commit 26786ae2)
Reviewed-on: https://gerrit.libreoffice.org/18054Reviewed-by: Michael Meeks <michael.meeks@collabora.com>
Tested-by: Michael Meeks <michael.meeks@collabora.com>