there's an error saving history state at exit is pointless and annoying.
Just notify the user and move on.
Patch by Mike Frysinger, tweaked and extended by Benno.


git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@5507 35c25a1d-7b9e-4130-9fde-d3aeb78583b8