BUG: fix fiber bundle color display

Check for fiber bundle display nodes and use the old method,
igoring the new scalar range options for models. Fixes bug
introduced with issue #3573 in svn revision 23083

Issue #3672


git-svn-id: http://svn.slicer.org/Slicer4/trunk@23118 3bd1e089-480b-0410-8dfb-8563597acbee