When switching navigation types, then switching back to the original...

When switching navigation types, then switching back to the original navigation type, qnet will no longer re-filter the data, but keep the old list of filtered data. Fixes #2144.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/trunk@6277 41f8697f-d340-4b68-9986-7bafba869bb8