Thorsten thought it might have been used for to the handling of the "Original
Size" functionality originally. That seems slightly broken currently in some
use cases, and this change doesn't make it any worse. (To see the brokenness,
play with resizing an image, reloading the document, and using "Original
Size". With the right sequence of actions, LO seems to think that the
"original size" is very small (1x1 pixel perhaps).)

Change-Id: I4e0852d2b367def5bc40baf95aac273d59731eec