modifiers at the "Write File" prompt were marked for translation via
gettext no-ops but never actually translated; also, in do_insertfile(),
use actual gettext calls instead of no-ops, for consistency


git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@3660 35c25a1d-7b9e-4130-9fde-d3aeb78583b8