BUG: Made color scalar bar RepositionableOff

This is a quick temporary fix for color scalar bar re-positioning
behavior which not works in horizontal mode.

For more details, see http://slicer-devel.65872.n3.nabble.com/Slice-annotations-comments-tp4032290p4032305.html

From: Alireza Mehrtash <mehrtash@bwh.harvard.edu>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23618 3bd1e089-480b-0410-8dfb-8563597acbee