fix bug in do_justify(): if all the text from the next line has been

fix bug in do_justify(): if all the text from the next line has been
moved to the current line and the next line has been deleted, continue
the justification loop from there and skip the respacing routine in
order to avoid running it more than once on the same line (since it
assumes that we've moved to the next line, which isn't true in that
case)

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@1839 35c25a1d-7b9e-4130-9fde-d3aeb78583b8