BUG: prevent crash reported in #2925 - missing annotation point

The fiducials did not load correctly so no coordinate exists.

The underling question of why the fiducials do not correctly
load from that scene is not resolved.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@21672 3bd1e089-480b-0410-8dfb-8563597acbee