fix regression caused by the justify overhaul: when justifying a quoted

fix regression caused by the justify overhaul: when justifying a quoted
paragraph, don't put the indentation of the first line at the beginning
of every broken line unless that indentation was at the beginning of
every line originally

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@2356 35c25a1d-7b9e-4130-9fde-d3aeb78583b8